Search results
Results From The WOW.Com Content Network
Translation initiation is the process by which the ribosome and its associated factors bind to an mRNA and are assembled at the start codon. This process is defined as either cap-dependent, in which the ribosome binds initially at the 5' cap and then travels to the stop codon, or as cap-independent, where the ribosome does not initially bind ...
Thus translation and transcription are parallel processes. Bacterial mRNA are usually polycistronic and contain multiple ribosome binding sites. Translation initiation is the most highly regulated step of protein synthesis in prokaryotes. [5] The rate of translation depends on two factors: the rate at which a ribosome is recruited to the RBS
Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as translation . All of these processes form part of the central dogma of molecular biology , which describes the flow of genetic information in a biological system.
The ribosome has two binding sites for tRNA. They are the aminoacyl site (abbreviated A), and the peptidyl site/ exit site (abbreviated P/E). Concerning the mRNA, the three sites are oriented 5' to 3' E-P-A, because ribosomes move toward the 3' end of mRNA. The A-site binds the incoming tRNA with the complementary codon on the mRNA.
The cap end of the mRNA, being the 5’ end, is brought to the complex where the 43S ribosomal complex can bind and scan the mRNA for the start codon. During this process, the 60S ribosomal subunit binds and the large 80S ribosomal complex is formed. The eIF4G plays a role, as it interacts with the polyA-binding protein, attracting the mRNA.
A number of bacterial mRNAs have no 5'UTR whatsoever, or a very short one. The complete 70S ribosome, with the help of IF2 (recruiting fMet-tRNA), [8] can simply start translating such a "leaderless" mRNA. [1] A number of factors modify the efficiency of leaderless initiation. A 5' phosphate group attached to the start codon seems near ...
The RNAs transcribed serve diverse functions. For example, structural components of the ribosome are transcribed by RNA polymerase I. Protein coding genes are transcribed by RNA polymerase II into messenger RNAs (mRNAs) that carry the information from DNA to the site of protein synthesis. [1]
IF-1 mutants can exhibit cold-sensitive phenotypes, indicating a role for the factor in cold shock adaptation. [15] Certain mutations also lead to o of genes at low temperatures, suggesting IF-1 is involved in gene regulation. [16] IF-1 actively modifies ribosome structure and dynamics during initiation, in addition to just blocking the A-site.