Initiation

In bacteria, transcription begins with the binding of RNA polymerase to the promoter DNA. RNA polymerase is an essential enzyme consisting of five subunits. Downstream of the promoter sequence of the -10 base pairs and protein sigma factor, is associated with help you to find the appropriate -35 at the start of ω1 subunit core enzyme 2α subunit, and the β subunit 1,1 β “subunit. When the RNA polymerase and σ factors are combined to form more complex in eukaryotes start of holoenzyme.Transcription. RNA polymerase of eukaryotic rather than to recognize the core promoter sequence directly, they recovered RNA polymerase and only after that. specific transcription factor transcription factor called binding of initiation of transcription is mediated linked to RNA polymerase promoter, the assembly was completed the RNA polymerase and. transcription factor does not bind to it, for the formation of the complex start. transcription of transcription of archaeal domain that binds to the promoter of is similar to transcription in eukaryotes.

Initiation

The first step of transcription, is an opening that identifies the start of the mRNA position and appropriate it. Due to the nature of the “out under” genetic code, the location of the start codon only, has the potential to determine the reading frame, false detection can lead to a complete distortion of messages as a result of a change in reading frame. Exact start is essential for an accurate translation. The genetic code, the start of a particular signal is not included. Rather, the dual function that is associated with the presence of two types of mRNA codons August methionine. One, met for use in normal-tRNAMets initiator tRNA and especially at first. Met-tRNAMet second, are used amino acid methionine at the position of the inside, in the process of expansion of the set, including reasonable-elongator only protein. (Initiation factor EIF of eukaryotic) initiation factor of several proteins that provide support to the ribosome during the initiation process.
When starting the process, it may be divided into separate steps several.
1. First, ribosome dissociation is called the 60’s and 40’s department in the configuration sub-unit of the two. Subunit can prevent spontaneous reassociation of connecting the initiation factor EIF-3 in the ribosomal small subunit.
2. Initiation factor 2 is an EIF-GTP-binding protein that recognizes a specific initiator tRNA to form a ternary complex and (A).
3. Ternary complex B is associated with the 40S ribosomal subunit.
4. 5 ‘end of the RNA cap structure is recognized by initiation factor EIF-4F. This factor, interacts with the cap structure in particular: Has division (see cap structure splicing). Combination of the user who started the cause of activation is 40S, subunit initiator tRNA, including the 5 ‘end of the mRNA. This type of start, is known as a cap-dependent start, which is the most common type of start. May be caused by a cap start mechanism independent of another start.
5. Move the 5 ‘untranslated end of the mRNA of the related subunit mRNA in until it reaches the codon of the first of August to become the start codon of the translation process. It requires energy (ATP), the process called scanning is started additional factors.
6. Subunit codons 60 begins to bind to the 40S subunit when it reaches the activation of 40S subunits. This reaction, to release the factors that start from the ribosome as this requires factor EIF-5 start of hydrolysis add EIF-2 bound GTP. As a result of the start process, the initiator will be placed in the collapse of the ribosomal P-80S ribosome site.The of 60S subunit and 40S. Subunit can prevent reassociation spontaneous intiation factor EIF-3.

The basic process of protein production, the addition of amino acids one by one to the end of the protein. This operation is performed by the ribosome. Selection of the type of amino acid to be added is determined by the mRNA molecule. Each amino acid, I was added to match the base sequence of the mRNA of the three. Type of amino acid of one particular possible is accepted only in each triplet such. Contiguous amino acids are added to the adaptive circuit to the nucleotide triplet continuous mRNA. As a result, I will determine the sequence of amino acids of the chain of amino acids nucleotide sequence of the mRNA template of the chain has been formed. It is found in the C-terminus of the peptide, and thus, the addition of amino acids, the transfer function – is said to be a carboxyl – amino.

carry the genetic information encoded as a ribonucleotide sequence of chromosome of the ribosome during mRNA. By translational machinery in the sequence of nucleotide triplets called codons ribonucleotides are “read”. Each triplet of these codes for a particular amino acid. Molecule of the ribosome translates the code to this specific sequence of amino acids. The ribosome is a multi-subunit structure containing the protein and ribosomal RNA. This is the “factory” is incorporated amino acid, the protein. (93 nucleotides from 74) small non-coding RNA chain, amino acids are transported ribosome mRNA. Of tRNA is, have the site of a site called anticodon and amino acid attachment. The RNA, to be complementary to RNA triplet, encoding the amino acid of the cargo in the anticodon triplet.

Aminoacyl-tRNA synthetase (enzyme) catalyzes the coupling between amino acids, that the anticodon sequence tRNA and requires a specific. The product of this reaction is an aminoacyl tRNA molecule. This aminoacyl-tRNA, codon of the mRNA moves to the ribosome that is matched to the base of the pair added to the tRNA anticodon specific. The ribosome has three sites for tRNA to bind. They are (E for short) exit point aminoacyl site (abbreviation), and peptidyl site (abbreviated P). ‘For mRNA for moving to end, 3 seats, EPA 5’ 3 of the mRNA is 3 ‘orientation from the ribosome. I will bind and tRNA codon additional site of mRNA is imminent. I will hold the polypeptide chain mRNA of P management is growing. TRNA in the E site does not have the amino acid.

Initially, when bound to the codon that corresponds to that of the mRNA, are on the site aminoacyl-tRNA. Thereafter, the amino acid sequence of the mRNA and form of the peptide bond between amino acids mRNA to one location is transmitted to the site of mRNA growth and loaded polypeptide chain on the P site. Transfer occurs, and amino acids to E site that was in the accused now site at polypeptide chain, the tRNA, the P, move the mRNA leave the E site to a site that you are in the site P without the tRNA is now , aminoacyl-tRNA other enters the site to repeat the process. After being added to the circuit a new amino acid, the energy provided by hydrolysis of GTP which is connected to EEF-2 and (prokaryotes) translocase EF-G, the termination codon ribosome at the 3 ‘end of (eukaryotic) I want to move down. Energy necessary for translation of proteins is important. For N protein-containing amino acids, the number of high-energy phosphate bond necessary for translation 4N-1. Translation rate is different, but it is significantly higher (up to 17-21 amino acid residues in the second) prokaryotic cells than (amino acid residues within 6-9 pieces second) eukaryotic cells.