Transfer RNA
The (abbreviated as tRNA of sRNA reduction of a rchaically of soluble RNA) transfer RNA, RNA that acts as a physical connection between the amino acid sequences of the (RNA and DNA) nucleotide sequence of the nucleic acid, generally 73-94 in length protein, an adapter molecule comprising a nucleotide. As indicated by the nucleotide sequence (codons) into messenger RNA stars (mRNA) 3, which is achieved by performing an amino acid protein synthesis machinery of the cell (ribozymes). Thus, mRNA is according to the genetic code, it is biological synthesis components required for translation of the protein, new proteins.
Specific nucleotide sequence determination of the mRNA protein product of the gene of the amino acid is transferred to RNA, and to determine the sequence of the genetic code corresponding to amino acids, and is included in the role of mRNA. One end of the mRNA corresponds to the genetic code of the nucleotide sequence of the three is called the anticodon. And is formed by the codons of mRNA in protein biosynthesis in the anticodon three base pairs. Each recognized by the mRNA specific mRNA which encodes the protein sequence of codons consecutive such. I have bound to an amino acid corresponding to the anti-codon sequence covalently attached to the other end of the mRNA. (In fact, to have so includes a plurality of codons that define the mRNA molecule number of the genetic code have the same amino acid, the anticodon different, any type of mRNA molecules, amino many types of mRNA has the body of each This may be associated with one type of I also have the same amino acid).
covalently bound to the end of the 3 ‘of the mRNA is catalyzed by enzymes called aminoacyl-tRNA synthetase. The mRNA during protein synthesis, with an amino acid (one of the eukaryotic to support an array of mRNA codon during decoding to be supplied to the ribosome by a protein called a bacterial bovine EF-Tu) elongation factor. If it matches the mRNA ribosomal mRNA of other connected to transfer peptide chain growing from the amino acids’ end attached to the 3 ‘3 end of the mRNA newly provided already anticodon mRNA is catalyzed by ribosomal reaction to be.
n is a unit consisting of three nucleotides corresponding to the three bases of the codon of mRNA anticodon [5]. The base pair and cans codons one or more specific sequences anticodon triplet, the amino acid and mRNA, respectively. Several anticodon comprising a may be paired with a plurality of codons due to phenomenon known as wobble base pairing. Hydrogen bond can be based on more than one position of codons pseudouridine and inosine, corresponding: Well, the first nucleotide of the anticodon, is was not found on mRNA of one of two. The genetic code, for example due to a single amino acid specified by the capabilities of the fourth position, the purine or pyrimidine and is generally at least, is encoded amino acid glycine codon sequences GGU, GGC, by the GGA GGG. 61 mRNA species of mRNA molecules and is to provide a one-to-one correspondence between the codons specifying the amino acids required by the cells. All codons that define the specific amino acids, the wobble base can be connected to a plurality of not necessarily, however, many cells containing mRNA species 61 below. The tRNA of 31, there is a need to translate the Sensukodon of 61 of all of the standard genetic code uniquely at least.
Ribosome, there are three binding sites for the molecule of mRNA covering the space between the ribosomal subunit of two: (aminoacyl), site E (peptidyl) (output) the P. Moreover, ribosome binding site other two for the mRNA used for mRNA or during decoding at the start of protein synthesis is present. These, T site (the name elongation factor Tu), where I is the (opening). By convention, the binding site of the tRNA, have placed the number of seconds is marked at the site of the small ribosomal subunit of the first in the list is large ribosomal subunit list. For example, the web site, in many cases, p-site and A-L27, as this is written E site / site P, and P / P, and E / E is by affinity labeling of AP Czernilofsky others such as L2, L14, L15, L16 of has been established, most binding protein. (. Sciences. Academy of Sciences Institute of Physics, National tulle Stone, USA, P 230-234,1974). After the initiation of translation has been completed, the first aminoacyl tRNA is ready for later extension cycle, and is disposed in P / P site. The translation elongation at the time, as part of a complex with a counterpart of archaea or eukaryotic (EF-TU) or (EEF-1), mRNA is bound to the ribosome elongation factor Tu first. TRNA binding site of this early, are called / T site. / The site of T, I live in the decoding site small ribosomal subunit half of the site, of the mRNA. consideration where the transfer in the decoding site of mRNA, is the codon of mRNA.
T-half site is located in the EEF-1 large ribosomal subunit or, of interaction EF-Tu and ribosome mainly. MRNA after decoding is complete, I’m ready for peptide bond the next aminoacyl-tRNA binds to site, to form the amino acid of the anchor. Transfer peptidyl-tRNA growth peptide binding aminoacyl-tRNA is bound to the P site site. After forming a peptide bond to the mRNA P / P, the site and carry the polypeptide chain mRNA is / Site deacylation, or the free 3 ‘end, and inside is growing. In order to enable the extension of the next cycle of the mRNA, then, it is located in the site of the E / E and P / P If you proceed with the binding site of the P / E and hybrid AP / completion of the previous cycle. TRNA and the P / P When you move to the site of the E / E and P / P, mRNA moves from one codon addition, it is ready for the next round of mRNA decoding, / T site is open. MRNA linked through sites E / E leaves the ribosome thereafter.