It before it was possible to examine the immunoglobulin genes directly, two hypotheses about the origin of these differences are present. Reproductive theory, the different strands of immunoglobulins and antibody repertoire is assumed that there is a single gene that is highly genetic. On the other hand, somatic diversification theory, during the life of the individual repertoires observed was proposed to be generated by a limited number of genetic V region sequences that undergo changes in B-cells. The antibody repertoire, in fact, cloning immunoglobulin genes are shown to be produced by DNA rearrangement during the development of B cells. As can be seen in this part of the head, DNA sequences encoding the V regions are attached to each locus by selecting from a relatively small group of gene segments inherited. Diversity is enhanced by the process of somatic hypermutation in mature activated cells. The concept of multiple genes of embryonic germ theory embodied, proof of true diversification theory of somatic cells, is essentially correct in this way.

non-lymphoid cells, but mature B lymphocytes is a considerable distance from some sequence encoding the region C, gene segment encoding the majority of the V region of an immunoglobulin chain, V-region sequences and n is , as a result of gene rearrangement, assembled is very close to the area C. Reorganization of the immunoglobulin genes when it became possible it with a restriction enzyme analysis of the first, consider the organization of the immunoglobulin genes in both non-lymphoid cells and B cells by Southern blotting , initially, I was discovered 25 years ago. In this step, chromosomal DNA was identified by hybridization with radiolabeled DNA probes specific for the DNA sequence is cleaved with the first restriction enzyme and the corresponding DNA fragments containing the C-region sequences and V-particularly . Is a germline DNA from non-lymphoid cells in the C-region sequences and V-determined from a sample of DNA fragments. However, the DNA of the antibody-producing B cells, the C-region sequences and V-, these indicate that the DNA rearrangement has occurred, the same DNA fragment on. Typical experiment with human DNA will be displayed in.

V region of the immunoglobulin heavy or light chain is encoded by a gene segment or a plurality of region V,. Light chain V regions for are encoded by DNA segments of the two separate. The first segment encoding the amino acids 95-101 of the first of the light chain, the V gene segment, V. second segment, the remaining portion of domain V (up to 13 amino acids) is called the code a large part of the domain The encoding, it is called a J gene segments or multiplexing.

Create an exon rearrangement leading to production of a complete immunoglobulin heavy chain gene, encoding the light chain V region of the whole shown in inches of bonding J gene segments and V, and not interrupted. The J gene segment, which is located far from the relatively area C, however, is located in the adjacent area C, and consolidated segment, V gene segment, J is close to the C-region sequences and V gene segments in unrearranged DNA I’m carrying the V gene. Gene rearrangement of V region, J segment is separated from the sequence of the C-region of the intron. In the experiment shown in germline DNA fragment identified by “V region probe” contains specific “C-field probe” and V gene segments, comprises a sequence of C region gene, and J segments actually You. I make the RNA of complete immunoglobulin light chain V region exons that binds the C-region sequences of splicing RNA transcription.

For simplicity as if there was no only one copy of each gene segment, so far, we have discussed the formation of a complete immunoglobulin V region sequences. In fact, multiple copies of the gene segments of all the germ cell DNA exists in. To assemble a V region to make the diversity of V region of an immunoglobulin, which is a random selection of the gene segments of one of each type. Gene segments of all decision not shown login using cloning and sequencing of the gene, as in the number of functional gene segment of each type in the human genome, it is not possible to encode a protein that they work There is no functional units accumulated mutations. Is referred to as a “false” They, because there in the DNA of the germ cells of many V and J gene segment D, and none of them is not necessary. This reduces the pressure on the gene of the development of any remains of the lead of a relatively large number of false segment intact. It is possible to undergo rearrangement as a functional gene segments Usually only a part of the pseudogene thereof, a substantial portion of the dislocation comprises a pseudo-gene, thus non-functional.

In budding yeast, suggesting an important role in the alignment of Hop2 proper homologous chromosomes during meiotic prophase, lack of Hop2 protein is formed extensive Shinaputonema non-homologous chromosomes between (SC). Hop2 act in the same way, and gene analysis, shows the two homologs of RecA RAD51 DMC1 protein, the EE. Therefore, hop2 mutant phenotype shows the importance of recombination mechanism to facilitate proper chromosome pairing. Dmc1/Rad51 recombinase Hop2 provided need to distinguish homologous sequences from heterologous in the process of homology search we. In this way, Hop2 absence non-homologous sequences between interaction is inappropriate stable, I will start the formation SC. Overexpression of RAD51 suppresses the defects in meiosis of hop2 mutant and DMC1 mainly. We, whereas require additional elements DMC1 such as Hop2, RAD51 concluded that to be able to perform homology search independently.

That the two modes of mismatch repair operates in patch mismatch repair and very short patch mismatch repair long bacteria are known. In order to protect the single base pair, patch mismatch repair system is very short, operated at a particular disorder. Thus, recombination of the hyper-specific marker patch mismatch repair action in a very short recombinant hetero intermediate, creating patchwork sequence, ie events, field repair of apparent multiple for the exchange. Disassemble the apparent heteroduplex DNA, recognizes a gap to be formed by strand exchange between the non-identical parent sequence sufficiently by preventing their formation, long patch mismatch repair is antirecombinagenic. In order to ensure the high fidelity of homologous recombination, this discrepancy stimulation antirecombination long patch mismatch repair, it is assumed that the “correction” system it. In suggesting a role of non-coding sequence or other error repeatedly as an element antirecombination of the chromosome, which, mitosis and chromosomal abnormalities compared to the high frequency of sister chromatid exchange (accurate chromosome stability in eukaryotes because it represents a rare event) that is recombinant and differentiate without the need for a geographically separated to provide a molecular mechanism.

Molecular mechanisms of meiotic recombination has been studied in budding yeast well. Double-strand break formed from SPO11, II topoisomerase homolog protein (the DSB), the process begins. DSB is completed, an end portion 5 thereof ‘is decomposed therefrom leading to DNA strand. It is thought to be used in the homology search (recombinase) enzyme strand exchange single-stranded DNA thereof. , Single-stranded DNA sequence homologous intrusion staining nonsister finally, this is, of double Holiday junction the crossovers are leading double Holiday junction and aggression to one end or middle / it was assumed that by resolution, and is formed mainly.

In budding yeast, the genetic research, it has the ability meiotic recombination mechanism detects the sequence homology between the location of the ectopic effective as the site of the allele are shown. I indicates that this observation has been made recombinant mediated homology search, throughout the genome. Meanwhile, fluorescence in situ hybridization (FISH), the binding of several homologs occurs even in the absence of recombination has been shown. In this way, it looks coupling mechanism that does not depend on recombination and meiotic recombination to work with homolog of the redundant circuit. However, it remains ratio of each mechanism homologs scheme is unknown.

In this study, we provide evidence that Hop2 is involved in meiotic recombination. Hop2 act, and epistasis analysis indicates the RAD51 DMC1 as that. Thus, heterologous synapses were observed to show the importance of recombination in the plant homologue method hop2 mutation. We are offering to run a new step downstream of meiotic recombination and RAD51 Hop2 DMC1, in this step, I guarantee the homology search efficient and accurate. In addition, I found that overproduction of RAD51 suppresses the meiotic recombination defect in DMC1, this suppression is not required to Hop2 protein. We suggest that the pathway of homologous recombination-mediated pairs is present. Not once RAD51, DMC1-dependent applications of other, more complex and Hop2/Mnd1 Hop2/Mnd1, or DMC1

Therefore, it is believed that the main function of the long Mutl and has adjusted the continuous process mismatch repair. However, recent studies, Mutl homologue most from an organism that has not been saved Muth indicates that associated with the low activity endonuclease, encoding the metal binding motif. To have been found in organisms that rely on DNA mismatch repair you do not disgruntled dependent only Mutl cognate bearing this activity, this finding reveals another important feature of the protein Mutl step in the direction discrimination. In this chapter, in order to explain how to Mutl the endonuclease activity and characterize the multiple functions of Mutl is regulated by the repair of other factors, we will discuss activities and structural features of the recently.

Mismatch repair DNA (MMR) is a pathway that is highly conserved play an important role in the maintenance of genomic stability. Specificity of the MMR is based on the generation insertion / deletion mispairs between the recombinant and DNA replication and base mismatch mainly. It suppresses homeologous recombination Further MMR, plays a role in DNA damage signaling in eukaryotic cells recently have been shown. Homolog of the eukaryotic and Mutl, MutLalpha MutSalpha and is an important player in MMR-related genome maintenance each MutS of Escherichia coli. For example, also are involved in DNA metabolism various routes, such as RPA and PCNA, protein component of many other, is essential for MMR. MMR defects is related to the whole genome instability such as abnormal predisposition and infertility division of mammals and hereditary non-polyposis colon cancer, resistant to chemotherapeutic agents particular, to cancer, some.

The participation of more than one stage of mismatch repair of DNA replication protein of (RPA) to (MMR), however, modulation of the function of the phase between different is unknown. Phosphorylation, we have shown here that you adjust the MMR in RPA function perhaps. In order to facilitate assembly of the starting complex was originally MMR, unphosphorylated RPA is associated with the double-stranded DNA nicks heteroaryl. By gap of single-stranded DNA obtained preferentially in the non-phosphorylated protein to connect, I stimulate the resection probably caused mismatch. Begins to phosphorylate wide resection as a result of reducing the DNA binding affinity of RPA Repeat DNA binding RPA. Therefore, the phase of DNA repair synthesis, easy, RPA was phosphorylated make available DNA template for the re-synthesis by DNA polymerase δ catalyst away from DNA. These observations, to support a model of a method for changing the DNA binding affinity for RPA phosphorylation meet the requirements of the differential stage of the MMR.

As a consequence of exposure to physical agents chemical and exogenous (eg, smoke benzo [a] pyrene, polychlorinated biphenyls, dioxins, and tobacco, DNA damage in cells, asbestos is accumulated over time , UV light, Rn), reactive metabolite, including NOS) and (ROS and nitrogen species endogenous active oxygen. Another source of DNA damage, is an error that occurred during the processing of the DNA of abnormal reaction and metabolism of normal DNA, including DNA replication, repair and recombination. Depending on many factors, including the DNA polymerase specific incorporation of nucleotides miss generates a base mismatches in DNA bases of DNA synthesis by varying the speed. Please refer have a copy of the low accuracy (such as Andersen. While cancer, in general, DNA polymerase, see Kunkel and (McCulloch, the subject of DNA polymerase overcome surrounding the specific sites of DNA damage etc. have a copy of the relatively high replication fidelity), and, in this issue). If it is not removed, DNA damage, has the potential to generate mutations in germ cells and somatic cells can be changed and diseases disorders that cause cell phenotype. To prevent these adverse effects and to protect the integrity of the genome and has several mechanisms to repair damaged DNA, cells prevents mutations thereby. Such a system is a critical path known as DNA mismatch repair.

Thus prevent the mutation, mismatch repair DNA of MMR that occur during DNA replication is permanently dividing cells. MMR defect, increased mutation rate spontaneous MMR, so have reduced the number of errors of replication-related. Hereditary and inactivation of MMR in human cells are associated with human cancers sporadic, MMR system is required for cell death in response to certain types of DNA damage and programmed cell cycle arrest and / or It is a. Therefore, prevention of mutagenesis in tumor formation in both short term and long term damage and cell severely eliminates, MMR plays a role in DNA damage response pathway.

And may play a direct role in the activation of transcription by combining factors associated with non-adjacent site where, DNA is the binding of factors involved in the formation of the initiation complex bending caused by transcription factors eukaryotic I will facilitate. Expression zinc finger transcription factor Sp1 of ubiquitously is involved in the regulation of cellular genes and other viruses. Recently, homologous proteins are described SP1 will represent the SP1 family of transcription factors. Speed ​​of bending of the induced DNA, we used the gel electrophoresis method for the analysis of the position and orientation by SP1 family of four different proteins that are related to consensus GC box we. We, it was found that the SP1 family proteins induces DNA bending asymmetric toward the main groove and the center angle, proceeds to the 3 ‘end box and GC. Zinc finger domain alone, was responsible for the introduction of this distortion. The size of the angle induced varies between different proteins. Hybrid proteins, and GC, the configuration of the mutation was shown that the magnitude of the angle is important for the binding affinity with the position of the center bending bending zinc finger 1 at the 3 ‘end of the box. Indicates that the insertion of the 5 BP between the housing and the TATA box is GC, or bending the GC box reversal induced by the protein significantly, Research transactivation dependent promoter Sp1 including the activity of the promoter It is shown that it may be important, to reduce the promoter activity. However, suggesting that it is not active enough for trans bent stimulating effect was not observed in co-transfection with the binding domain of the DNA of Sp1 in Drosophila SL-2 cells.

There is room for debate the role of MutS ATP-ase of mismatch repair in. In order to clarify the function of this activity further, we examined the effect on MutS interaction ofEscherichia car of adenine nucleotides of double-stranded DNA hetero and homo duplex. In contrast to the previous results with human MutSα, we may be sufficient physical block to maintain the Mg2 + of MutS · the stable complex formed in the presence of ATP to one end of a linear heteroduplex found. MutS of a surface plasmon resonance analysis of low ionic strength, indicating that it is dependent on the nature of the nucleotide MutS the life of the double-stranded DNA heterodimeric complex is bound there. Complex in the absence of a base, or obtained in the presence of ADP to, Mg2 +, adenosine 5′-(β, γ-imino) triphosphate Mg2 +, a-, complex manufacturing, in the presence of ATP Mg2 +, or (without Mg 2 +) ATP is resistant to degradation of ATP entry at the time of (AMPPNP) · while subject to rapid degradation of contamination by acid ATP. Result of removal of specificity for mispaired DNA, reduction of MutS affinity of hetero (Mg2 + without) ATP and Mg2 + of AMPPNP · does little effect on double-stranded affinity homo at a salt concentration physiological . Conversely, in the absence of nucleotides, mismatch or high specificity was observed in the presence of ADP. Effect of ADP only on the hetero affinity to reduce the double-stranded DNA MutS affinity homo, but is limited.

DNA biosynthesis errors that escape the editing function of the DNA polymerase is corrected by mismatch repair. Mismatch repair is characterized bacteria originally, similar system has been identified in eukaryotes, defects in mammalian time, has been implicated in tumor progression.

Removal of DNA synthesis error in these systems depends on the secondary coil signals serves to distinguish DNA that is synthesized de novo in the template strand. In Escherichia coli, these signals is based on the model of adenine methylation D to be replicated (2) new hemi-methylated DNA of (GATC) sequence. It is initiated by the mismatch recognition, repair MutS · heterocomplex of mounting Mutl · will help to activate the (GATC) endonuclease Azimut D in the ATP-dependent reactions by MutS. Active Chelsea cleaves the methylated strand of (GATC) sequence hemimodified D which may be disposed on either side of the mismatch. Since II, entering the spiral of Azimut production strand breaks and DNA helicase direction bias is sufficient MutS · heterodimer assembly Mutl · also to allow the traces to the back gap. In this orientation, is dependent on the signaling relationship between the two parts of the DNA helix activation loop of cropping system in the direction of vacation is developed. Fact Mutl of MutS and that it is sufficient for that purpose, which means that one or both of these activities to function in signal transmission between the DNA site of two.

Several models have been proposed to explain the interaction of DNA two sites oriented methyl reaction. Mutl dependent cleavage of oligonucleotide duplexes second that led to the assumption that it is brought close to the DNA bending by both objects evidence of recent and MutS exists that there is a double in mismatch oligonucleotide pairing error activates the downstream signal of the signaling activity Mutl interface of the MutS can activate the (GATC) sequence Azimut AD. However, the observed activation efficiency is active in the length of 1000 base pairs IIA of mismatch low several hundred times higher than that observed for D of (GATC) cut in trans-activation experiments Azimut these. The DNA bending mechanism, and also, while can be described activation cleavage Muth ad (GATC) sequence, the activation of the direction-dependent cropping systems and Mutl-, it is the chain breaks, the MutS or not covered I followed the.

Impact analysis of the ATP mismatches leaf in the presence of ATP and more hetero · hMSH6 by spiral of MSH2 its shown in the interaction of human MutSα linear hetero, is a circular DNA or avidin Terminal Block – biotin. This suggests that the MutS homologue in the presence of ATP to form a sliding clamp helix. However, it is held by two different mechanisms for the movement of the first bracket. Model adjusts the conformation of a protein with a direct movement of the slide clamp spiral refers to hydrolysis and ATP binding by hMutSα bound to DNA. Can be distributed free of charge in the spiral, deposit mismatch recognition of another hMutSα · ADP complex in the nucleotide exchange factor quality mismatches to promote the formation of complex hMutSα · ATP. In this mechanism, ATP hydrolysis takes place after the release of the DNA, are used for the recovery of non-protein conjugates. These models, whether it has been confirmed by DNA-bound form of the protein, ATP hydrolysis and whether the target movement of DNA differ in the requirements for mismatch recognition ADP.

Mismatch repair mechanism is most detailed in E. coli, E. coli reaction was dissolved in purified systems. Repair is focused on transient absence daughter strand of the replication fork (GATC) methylation d in DNA newly synthesized. It is initiated by the binding of MutS to Mutl mismatch and have adopted the ATP-dependent DNA repair after hetero of the MutS. Ternary complex of hetero MutS • • is sufficient to activate D of Azimut incision of unmethylated strand (GATC) endonuclease activity assembly Mutl. Instruct the repair new DNA strands, acts as an entry point of the cutting system, disconnection of the subsequent circuit is the actual signal consisting DNA helicase II, with an appropriate single-stranded nuclease. The pairing 5 ‘to 3’ hydrolytic activity mis-3 ‘-to-5:00 thread suspended Azimut 5’, there is a need, but the mismatch. Ligase, to restore the integrity of shared spiral gap, and ‘is required when Muttonikku is 3 introduced exonuclease’ repair of the DNA polymerase III holoenzim then.

Mammalian cell extract supports such reactions is indicated by (gap or nickname) strand breaks can be repaired but to reside the non-compliance ‘or 5’ 3. Major protein for the initiation of mismatch repair of eukaryotic organisms, is a cognate Mutl and MutS of bacteria. Port 2 mismatch recognition activity of eukaryotic, MutSα and (MSH2 • MSH6 hetero) MutSβ (MSH2 • MSH3 hetero), MutSα but is the responsibility of the event mismatch repair in most mammalian cells probably. Homologue of eukaryotic Mutl functions as a hetero MLH1 can function as a common subunit. The best (MLH1 • PMS2 heterodimer), is separated from both yeast and human (a MLH1 • PMS1 complex), these features are MutLα.

DNA binding protein replication clamp PCNA, RFC-clamp loader, single-stranded DNA binding protein RPA, exonuclease I, and DNA polymerase δ: the study of mammalian reaction extract, in addition to MutLαMutSα and MutSβ in mismatch repair for the participants, HMGB1 it was involved, the activities of six. Surprisingly, as the 3 ‘, in the absence of other proteins necessary for 3′-led and repair of 5′-GG or GT mismatch in the extraction of cells of human and mouse to 5’-polarity ExoI hydrolysis of double-stranded DNA,. However, it is much less than the increase to 150 times by MSH2 deficiency HPRT volatility of these cells, extract from the line of mouse ExoI cells, insertion / deletion of a single base dinucleotide and important activities had increased 30-fold and I was holding the hetero. Spectrum of HPRT mutations have not been established, such as Wei. The study not only suggests that it plays an important role in MutSα-dependent repair of base mispairs underlying ExoI, the cutting operation an alternative, these data can be made to function insertion / deletion mismatch correction I could.

The observations of these results led to the system some friendly that support participants, and ordered the excision repair and causes mismatch. MutSα, MutLα, ExoI, simple and most of them are composed of RPA. Hydrolysis is a mismatch cause in this system, but to manage the resection always, you can run the 5 ‘to 3’ from the participants. It is not a MutLα required for this system, but it mismatch dependence of the hydrolysis reaction does not improve by suppressing the mismatch of ExoI without DNA.

System that MutSα, MutLα, ExoI, and to support the removal of two-way to complement the RPA in RFC and PCNA, resection to receive that is, place the non-compliance or 5 ‘or 3’ led by the participants. Unlike the simple 5 ‘to 3’ reaction, 3 ‘led resection is dependent PCNA MutLα completely, and RFC. RFC plays two roles in the activation of clear 3 ‘oriented resection. It acts directly to ‘not required for activation of oriented excision, mismatch ExoI mediated 5′ 3 to suppress the hydrolysis’ according to gap or to 3 ‘3 position nickname function as a load PCNA loader in the form of PCNA You. The activity of ExoI other than those used in this study, the 3 ‘-oriented resection of this system for ExoI, ExoI active site mutant was therefore does not support the hydrolysis intact and without exonuclease activity. The addition of DNA polymerase δ in six components these is a system that supports the mismatch repair reaction can be oriented in the direction of the rest which is located in the non-compliant ‘or 5′ 3. As well as the 5’-oriented resection, without independent MutLα necessary to repair synthesis steps of 5 ‘-oriented repair reaction in this system, it is RFC and PCNA.

The tasks described here, shows the function of ExoI and MutLα in mismatch repair of human. MutLα indicates that there is a potential endonuclease that is activated ATP-dependent mismatch, MutSα-, RFC-, and PCNA-we. Hetero cutting this 4 protein system is broken towards the direction of refraction is biased strongly. Mismatch, including the span segment was cut from the action “of the 5 ‘to 3 of MutSα activity ExoI then by a two-strand breaks.

Packaging of DNA by herpes virus and double-stranded DNA bacteriophage is driven by molecular machines powerful assembly to the portal vertex of professional head empty. – 11 or bike and terminase, large small terminase dodecameric portal pentameric 12 Merrick: T4 phage packaging machine is made up of three components. These components interact dynamically orchestration of a complex series of reactions to give a head full of DNA containing the viral genome per capita. In this case, I’m using to analyze the structure directly connected, and mutagenesis analysis of the interaction between portals and motor protein. Our results, I have shown that the binding site is located in the control ATP hydrolysis subdomain II of GP17.

Mutation of the major residue of this site leads to phenotype or temperature-sensitive zero. Turn – – helix (HLH) interacts with the portal save helix part of this site. Recombinant peptide HLH is competing with GP17 for translocation and portal block DNA binding. Loop residues while Report portal interaction proton pump centers, obviously, spiral provides specificity to capture pro head fellow. The observations These results lead to the possibility that HLH unique portal interactive symmetrical mismatched complex acts as a lever to position the trigger ATP hydrolysis and arginine finger. Transient binding of critical engine parts, sub-domain I is (ATP binding) and (movement of DNA) C-domain subdomain II (control ATP hydrolysis), interaction of the portal motor, and hydrolysis of ATP You can provide a tight coupling between the DNA transfer.

Peptide nucleic acid (PNA) is a synthetic mimic of DNA that acts as a vehicle for anti-gene applications and antisense. In recent years, the PNA is an antisense agent highly effective in cell culture towards the end of the 5 ‘UTR of the luciferase mRNA was shown. The PNA, it is directed to the RNA component of the enzyme Another application is for the inhibition of the human telomerase activity. Furthermore, suitable methods of cellular uptake of PNA is shown.

Chemical composition of the PNA includes a peptide and DNA. N-(2 – aminoethyl) – glycine backbone of PNA, the sugar of DNA – are very different from the phosphate backbone. NMR structure of the PNA-DNA hybrid, discloses a spiral that has a component B-DNA and A-(8). PNA is, it contains a nucleobase same DNA, Watson complementary strand of PNA DNA, or RNA – are oriented to generate a click interaction. The hetero of PNA, a large thermal stability, it must be because the charge does not exist on the backbone of “peptide-like” the PNA probably in terms of double-stranded nucleic acid. Increased thermal stability of double-stranded PNA heteroaryl seems to be independent on the ionic strength of the solvent.

The PNA has been applied to investigate the substrate specificity of the helicase recently. Helicases are enzymes replication, recombination, involved in various aspects of nucleic acid metabolism, including repair track. The helicase, be converted into chemical energy of ATP hydrolysis into mechanical energy necessary to develop a double-stranded nucleic acids has been proposed. DDA is a helicase from bacteriophage T4 that are involved in recombination with T4 DNA replication. Is stimulated upon binding single-stranded nucleic acids is possible to cause the movement of one helicase stranded DNA in (ssDNA) in most of the ATP-ase activity of helicases, including DDA. PNA is required for development that is based on double-stranded DNA in order to investigate the enzyme-DNA interactions specific to change occurs on one of the thread.

The rate-limiting step for unwinding, expansion of DNA-PNA heterodimer two to suggest that a specific interaction between the backbone of evacuation strand of DNA and the enzyme is not included, it is not changed It was as effective as stranded DNA substrate. In contrast, strong helicase, and suggests that the specific interaction between the two chains are required during development, from hepatitis C virus, substitution of one strand of the DNA duplex substrate PNA chain NS3 I inhibited the development activities of the helicase. Thus, in addition to its role as jean or antisense agent, PNA is used as a sample for the enzyme, nucleic acid interactions.

The lack of cost PNA backbone, the PN A which may be, for example, to improve by adding charged amino acids such as lysine, may lead to solubility relatively low. With the low solubility of PNA, it is the tendency of the PNA-alone unit. The formation of these components must be considered or PNA antisense application Gene. In the studies presented here, PNA indicate that extends to non-sequence specific interaction properties of a single unit having a single-stranded DNA.

May be useful as biochemical tools for the further understanding of the regulation of this mechanism for repair in turn, MutS ATPase in mismatch repair functions suitable for the analysis of potential inhibitors of the activity important role in the activity. The inspired us to analyze the effect of this compound on the ATP-ase activity, facts ATP-ase activity of several members of the ABC superfamily that is inhibited by vanadate in the MutS. In this study, in fact, ATP-ase activity and decavanadate that have been shown to orthovanadate inhibition of degree less MutS of Escherichia coli and Pseudomonas aeruginosa pus. Further, that by affecting the MutS-DNA-binding ability of the compound to inhibit partially and it has the activity of MutS protein aggregation are shown. As in the case of ATP-ase some, it discloses the Walker motif is involved in the binding of orthovanadate, ABC is inhibited by orthovanadate, we, the excellent fit in the structure of these to find, we compared the structure of the region of 17 amino acids, including the Walker motif of MutS and ATP-ase of multiple. It also embarked on a theoretical study, we propose a model for the interaction of decavanadate and MutS area contain the motif of Walker

Repair of mismatched base pairs of DNA, to ensure the genomic stability of almost all organisms. Major source of contradiction is a mis-pairing between DNA recombination events and DNA replication. The (PMS), failure to correct the results of the contradiction of these meiosis after separation genomic instability and DNA mutation rate increase, and microsatellite instability. Nowell lobes and as recommended 20 years ago, genetic instability, predispose cells to malignant change. Code defect inherited gene is various, including (HNPCC) hereditary nonpolyposis colorectal cancer called colon, endometrium, ovary, stomach, small intestine, kidney, ureter, are collectively referred to DNA mismatch repair technology mouse and certainly people be susceptible to development of cancer in organs. Further microsatellite instability, and is connected to the majority of sporadic tumors.

MutS protein with the Mutl includes a mismatch repair system and the most characteristic, homologues of these proteins are found in mammals prokaryotes, archaea, yeast, Xenopus, and Drosophila. I shows an example of how a mismatch is repaired direction specifically in the repair mechanism that is reconstituted with in vitro of ED. It is necessary to introduce the section of the fiber that is targeted for repair ATP start of mismatch repair MutS, Mutl, and Azimut. I recognizes the insertion or deletion of base pair mismatch of 1-4 nucleotides in one chain of MutS. It was also found that by moving the MutS DNA of ATP-ase, to promote the formation of the DNA strand. Activate Azimut is a methylation-specific endonuclease and potential sequence in the presence of MutS and Mutl of ATP, together. If the replication error caused by you, the Chelsea, the newly synthesized, disagreement, cutting the 5 ‘side to the sequence d to methylation daughter chain. The template strand in wild-type E. coli, it is resistant to cutting of Azimut and methylation. The next of DNA repair by creating a substrate for exonuclease specific single-stranded to remove nucleotides nickname made by disgruntled Mutl and MutS of even more than it mispaired bases, to be active UvrD helicase to unwind the DNA What is needed in the stage of. Further Mutl and MutS in, it is possible to play a role in the selection of DNA polymerase III holoenzim to fill the gap in the final stage of mismatch repair.

In eukaryotes, Mutl homologs have been identified as PMS and MLH. The gene, that same Mutl phase and clone was named phenotype of PMS separation of meiosis after the advance. MutS homologs are known as the best MSH protein, as discrepancy, we recognize the heterologies in the DNA duplex. Of MutS, as protein in E. coli, eukaryotic  homologs of PMSS MLHs and is essential for DNA mismatch repair. More than 50% of the reported cases, mutations in PMS2 gene MSH2, PMS1 followed by mutation of the gene encoding the human MLH1 account for HNPCC. Recently, and MLH1 mutations identified in lymphoma cell lines and human leukemia. The connection between the DNA mismatch repair and cancer susceptibility has been established, the relationship between tissue-specific development of the cancer protein and DNA, is unknown. For example, null mutants of PMS2, both alleles of MSH2 has deficient knockout mice, viable and is affected by lymphoma in colon cancer, but it was not a result of a mouse phenotype of male sterility. In humans in particular, Mutl homolog in eukaryotes is clearly important for normal cell growth. However, the exact activities of these proteins have been determined.

Has a Mutl storage space to 300 residues in the N, member of the family of all, end the C-terminal region completely different from 300 to residue. They form a heterodimer in solution or homo frequently. Is stored in a region corresponding to more than 50% of the missense mutations found in human MLH1 in HNPCC, most of the mutations reported in the mutator phenotype dominant EF Mutl is restricted to the N-terminal region are. In E. coli that each component involved in DNA mismatch repair and even try to assign a biochemical activity Mutl simple is established, it is not successful. The JE Mutl, to mediate the interaction with MutS mismatch recognition protein with endonuclease Muth has been proposed. The MutS Mutl of, connecting lines formed in the hetero-electron microscopy has been shown. I will add the space Mutl of MutS in DNA fingerprinting has also expanded dramatically. However, it Mutl to interact with DNA directly is shown. Can cause the interaction between Mutl change of the DNA fingerprint of the MutS. Evidence for the physical interaction of UvrD between Mutl have been reported recently. To increase the helicase repair site, whether you interact with any Mutl switch from Chelsea and activation Muth, it is unclear Mutl.

In addition to HNPCC, MMR defect is associated with sporadic colorectal, endometrial, stomach cancer. Unlike the case of HNPCC, but the majority of cancer sporadic these rather than have identified mutations in MSH2 and MLH1, transcriptional epigenetic silencing is associated with a phenotype of MSI. Specifically, methylation of MLH1 promoter, is associated with a complete loss of protein expression. In addition to the functional inactivation of the MMR system of a mammal by epigenetic mechanisms and genetic protein loss, MMR Defect is due to the overexpression of protein MSH3 Through the joint efforts of Genes MSH3 and adjacent site DHFR. Excess MSH3 full usamotyava MSH2, MSH2 by it – it is possible to prevent the formation of MSH6 complex, to produce a anMSH6mutant equivalent. Finally, it is possible to exert dominantnegative effect was found to HNPCCassociated PMS2 nonsense mutation.

Spontaneous mutation rate, the spectrum of HPRT gene was obtained. Human tumor cell lines MMR defect. Mutations in the forward gene increased several hundred-fold in human tumor cell lines that are deficient in MSH2 and theHPRT MLH1, and increases in proportion, considering a frame from mutation INC1-1 nucleotide substitution. As with MMR-deficient yeast, these sequences, indicates that for the accumulation of protein inactivation, “in jeopardy” and especially that, Monoran is a hot spot frame events in tumor cells Mutation. Indeed, frame shift in mono nucleotides, TGF-pass and APC Both genes are important in colon tumorigenesis have been identified Tumor cells having the phenotype of MSI. HHUA human tumor cell line is deficient in MSH6 and MSH3, the chromosomal transfer experiments, the generation of cell lines is insufficient allowed in only one of the protein.
Study of mutations and microsatellite instability in cell lines of these HPRT Able to repair extrahelical chain size of MSH6 is 1-4 NT is shown, while the I will remove the line MSH3 2-4 NT size. Contrast to the yeast MMR The MSH3/MSH6 functional redundancy system above, it is seen in 1-2 NT for lines, MSH3 is only able to repair the line is greater than 2 HCl. Derivative HHUA, it is assumed to be increasing base substitution mutation MSH3, the failure rate of only surprisingly. In human cells, this means that it may be involved in adjusting the MSH3 intermediate base substitutions. MMR systems in mammals are involved in somatic hypermutation of immunoglobulin genes process variables in response to antigen stimulation, to generate high affinity antibodies. Several studies in other studies, no spectrum, the frequency of hypermutation is changed in MMR-deficient mice is shown, hypermutation full level for MMR It is shown to require a functioning system. Finally, in some studies, involvement of the MMR system has been reported in the course of somatic hypermutation. Recent data shows a serious confusion

As a model of human disease, of MSH2, MSH3, MSH6, knockout mouse This is done or PMS1, PMS2, MLH1,, except all MSH3-deficient animals and PMS1 showed an increased incidence of various Cancer of the internal organs. Provided by genetic studies of yeast, rather than the MMR defect completely, MSH6 mouse is a mouse MSH2 identical with a spectrum of different tumor from knockoutMsh6 MSH3 mouse and double mouse MSH2. Interestingly, there is a possibility that it has a spectrum of different tumors, reflecting the minor role of MLH1-MLH3 and MLH1, PMS1 in mutation avoidance Pms6 mouse and MLH1, both minor differences in mutation rate, show. Mutations either a spectrum MSH6, Each one or PMS2 knockout mice containing Lazi SUPF forward mutation reporter system has been reported. In contrast, PMS2 tissue-specific tumors were observed in mice showed a comparable increase in the mutation frequency is SUPF all tissues examined. The MMR machinery, the popularity of frame mutation in the spectrum of PMS2 mouse is consistent with the general consensus is that it plays a major role in correcting the error of the deviation of the DNA polymerase. The study of lacImutation, as expected with a base substitution, I found a inMsh2mice the mutation frequency was increased mainly. Interestingly the tumor tissue, and comparison

By eliminating the MMR system, it is in the development of a high mutation rate Were maintained under conditions for adjusting that was observed in bacterial cells The many generations that have concentrated the mutator, and be the result Selection process. For example, mutation if there is a de ¬] ED site The increased 100 fold in MMR-deficient cells, selection for mutations in this gene locus will Of the mutants that were selected, the concentration becomes 100 times the MMR deficient cells Population. In fact, the continuous selection of the direct multiple mutations Cell population obtained is made up in the MMR-deficient mutator mainly. In addition to to speed up the mutator phenotype and adjusting the generated Sequence differences that can require recombination barrier low-level I’m contributing to the differentiation process of the bacteria. Mutator phenotype of the thing It may be advantageous under conditions selective, there is no measurable negative electrode it Bacterial cells is a non-selective support for many generations, the effect of the above; Mutation load and strain the entire ¬ “-ness as much as possible.

Evolution of MMR-deficient mutator may be important for the emergence of bacterial pathogens that need fast in the laboratory under controlled conditions I will adapt to the new source. For example, more than 1% of Salmonella and E. coli bacteria  has 30% of the infection green pus pus isolates in the lungs of cystic chronically strong mutator phenotype isolates of enterica | which is a sclerosis patients mutator. In addition, both of which are associated with a defect MMR of high-level phase change pathogenic meningitis. As mentioned above, the results of the phase deviation from the on / off framework mutations, and is elevated in the absence of functional MMR system significantly in mono 7C manner. Finally, it may be associated with mutations multistep process observation of bacteria requires the development of cancer in a mammal, or can serve as a model of the relationship between MMR defects, promotes the formation of tumors

Oxidative DNA damage is a source of mutations in living cells. All living organisms have evolved mechanisms to protect against oxidative damage, but little is known, such as Pseudomonas, the mechanism nonenteric bacteria thereof. You have examined the involvement of DNA protective enzymes in foil oxidized guanine repair enzymes to avoid mutations hunger Pseudomonas. In addition, we, involvement putida DNA polymerase V homolog RulAB stationary phase mutagenesis to investigate the possible connection between oxidative damage to DNA, and error-prone in the P.. Our results, Mutt GO repair enzymes MutY, and MutM has been shown to participate in the prevention of base substitution mutations at carbon starvation P. putida. Interestingly, the effect of antimutator dog is dependent on the growth phase of bacteria.

In spite of the lack of severe phenotype mutator that causes the dog of bacterial carbon starvation, twice only increased the effect on the rate of growth observed bacterial mutation. In cells dog actively growing well, this is an indication that you have a backup system to complement the lack of this enzyme. The knockout of MutM, is localization, has not changed the frequency spectrum of mutations in mutation. The DSS, to protect DNA from oxidative damage is known. DPS-defective P. putida cells found We are sensitive to abrupt exposure of hydrogen peroxide than the wild-type cells. At the same time, the absence of DPS does not affect the accumulation of mutations in a population of bacteria starvation. Therefore, only if the bacteria are exposed to external agents, leading to not to oxidative DNA damage of under physiological conditions, protective role of DPS is possible to be essential for the integrity of the genome is. Putida introduction of the Y-family DNA polymerase PolV rulAB homolog of P. Increase the percentage of base substitution of G between the mutation that occurs during the fasting state to B. Making a synthesis overcome past the bases the damaged DNA is PolV since known, our results could indicate that an important source of bacterial mutation hunger adenine oxidation products .

Bacteria, has spent most of the time in the starvation conditions in which their growth is suppressed by insufficient energy. However, the population of the stationary phase bacteria cause mutations, and have received rapid development. Mutagenesis that occurs in idle cell, is called mutation stationary phase or adaptive mutation. Bacteria has a stress response of some to provide a method that can mutation rate increases in stationary phase cells. The oxidative DNA damage is an important source of mutagenesis. This, 7,8 – dihydro -8 – the formation of oxo-2, that can lead to mutations in the -30 Lee · deoxyguanin stationary phase E. coli known. Further, the products of oxidative damage to adenine, to be mutagenic is shown. However, to date, interest is to obtain much oxidation products thereof.

Chelsea protein (229 residues, 28 KD) is a molecule of bracket-like decision to separate the main two subdomains, cleft by a large-scale. To form a spiral of mixed leaf b A, B, and C,, sub-domain of the N, are included until the 145-120 and 83 from the remaining one. Formation of spiral 229, D 148 and from 117 from residue 90 of the sub-domain, C is, contains the AB hairpin F, and anti-parallel B sheet and endpoints and E,. Two sub-domains is associated with a 3 polypeptide linker and, filled with the area of ​​hydrophobic residues. The connection interface provides the flexibility to enable may be two sub-domains rotate relative to each other.

Despite remarkable precision copy DNA polymerase occurs at a frequency error DNA can be measured. Lead to mutations that some errors increase the viability of organisms, many mutations are harmful. Evolved a complex system for monitoring the genome for DNA damage and mutation, choice is to repair these defects as this. The endonuclease (except SS pairs) weak base mismatch and Muth protein of E. coli is an enzyme multimeric complexes that work to repair the mismatch in different directions by one nucleotide deletions four insertion or small.

Figure 1 shows the role of Mutl and MutS of the Azimut-oriented methyl mismatch repair. After MutS, mismatch repair protein of another that is associated with the complex Mutl this time, to recognize, errors, activate the Azimut of endonuclease activity potential. Chelsea is split on one side of the gap half of methyl (GATC) sequence. Depending on the Muttokatto whether the end of the exonuclease and exonuclease VII or mismatch 5 ‘or 3’, after disgruntled gaps and final, removing portions of the DNA I, (along with the MutS of, helicase II and Mutl) will be used. Repair synthesis followed by ligation restores the wild-type sequence of double-stranded DNA. Before going on to the next section, please reload the molecule.

Chelsea active site is located in the cleft between the C-arm of the molecule and the N-side. Slit is similar to the broad and deep is the 12-14 angstroms 15-18 angstroms of restriction endonuclease many. 7 base pairs of the DNA binding cleft contact B-DNA. Glu77, Asp70 DNA binding cleft, and 79 three residues Lys is important for endonuclease cleavage. These residues have formed catalytic triad forms the D (X) 6-30 (E / D) XK. It triplets such as this is important for the catalytic activity of several enzymes constraint II are known.

The binding cleft, residues other two Phe94 and Asp91, are highly conserved. To solvent exposure completely in the free enzyme is known to feature a clear Asp91, Phe94. By probably, do you help to DNA recognition, to be inserted in between a pair of the main board, which keep the DNA in place.

Magnesium ions are required for cleavage of Muth of the target DNA sequence. Reaction of Chelsea and Mg2 + ions are the same as those of the EcoRV restriction endonuclease for displaying structural homology probably. Ions was shown to be adjusted Glu45 Hano Mg2 at EcoRV + catalysis is important. It is Glu56, is a waterborne Glu77 hydrogen bond similar to Azimut residue.

Muth, must be activated by Mutl and MutS for DNA cleavage. The exact mechanism of activation are known, but it does not seem as C-arm pivot with respect to the N-side opening and closing of the DNA-binding cleft. This is the on and off of the catalytic activity. It seems to include the C-terminal helix F. functions as a kind of molecular switch that the “push” by Mutl this spiral of the MutS, activate the Azimut of endonuclease activity potential mobile movement you may have.

Chelsea is crystallized conformation of two. The first structure, it indicates to have the F helix of AA close crack and conformation of the active enzyme is packed in tightly structure probably. Extending the solution probably has a helical structure and F more open, the second structure is a non-active form of the enzyme. The difference in packing F helix, the mascara suggests that it plays a role as a lever, which is realized by Mutl and MutS in really.

The Chelsea, a similar activity with restriction enzymes, therefore, is interested in you have a structural similarity with PvuII and significant homology with Sau3AI it. Further, as described above, the catalyst is found triad Muth Type D (X) 6-30 (E / D) XK. Eco RI, in PvuII, this motif is included in the active site of the restriction enzyme of many, including the Bam HI Eco RV, and Fok I,.

There is a big difference these enzymes. For example, a dimer Some of these, some are monomers, they show specificity for different DNA sequences. However, the presence of a motif common descended from an ancestor common proteins suggest that homologs of evolution is i.e. they. The ability of bacteria, may have evolved from the basic functions of DNA repair in order to protect from virus attacks by DNA restriction.

Chelsea and Mutl and of MutS is essential for initiation of DNA methyl directed mismatch repair to correct the errors that occur during replication of DNA in E. coli. Newly synthesized, Azimut is 5 ‘sequence of D semi-methylated double to cut the chain of methylation daughter (GATC). I need the recognition of DNA mismatch due to Mutl Azimut activation of the MutS. And sequence homology to the structural similarity of the endonuclease in PvuII and with Sau3AI, Chelsea, suggesting the descendants endonuclease thing from a common ancestor type II limit and indicates the structural similarity in the PvuII and sequence , with Sau3AI by various amendments, shows a strong relationship between these enzymes.

Of MutS, Azimut and Mutl is a major protein of three to start the methyl-directed DNA mismatch repair to correct mistakes made during DNA replication in E. coli. Newly synthesized, Azimut is 5 ‘sequence of D semi-methylated double to cut the chain of methylation daughter (GATC). I need the recognition of DNA mismatch due to Mutl Azimut activation of the MutS. We crystallizes in space group two solutions Muth resolution structure of the 2,3 and 1,7 respectively. Relative rotation to be disclosed by the comparison of the crystal structure from each other, Muth active site is located at the interface of subdomains between the two that may modulate the activity of nucleases this. Relative movement of the Chelsea of ​​two sub-domains were correlated with the position to issue a C-terminal helix. Mutl and MutS of this helix, which appears to function as a molecular lever through it that you may want to report the detection of activation Azimut and DNA mismatch. Structural similarity is related to these enzymes clearly PvuII endonuclease and has a sequence homology with Sau3AI, in Chelsea, various modifications, II type restrictions descendants endonuclease thing from a common ancestor to this I suggest.