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The entire process is called gene expression. In translation, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and performs its functions in the cell. The polypeptide can also start folding during protein synthesis. [1]
An mRNA molecule is said to be monocistronic when it contains the genetic information to translate only a single protein chain (polypeptide). This is the case for most of the eukaryotic mRNAs. [ 28 ] [ 29 ] On the other hand, polycistronic mRNA carries several open reading frames (ORFs), each of which is translated into a polypeptide.
Translation is one of the key energy consumers in cells, hence it is strictly regulated. Numerous mechanisms have evolved that control and regulate translation in eukaryotes as well as prokaryotes. Regulation of translation can impact the global rate of protein synthesis which is closely coupled to the metabolic and proliferative state of a cell.
Several ribosomes synthesizing a polypeptide on the same mRNA strand. A polyribosome (or polysome or ergosome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”. [1] It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.
The canonical tree of life is the lineage of the translation system. [citation needed] LSU rRNA subtypes have been called ribozymes because ribosomal proteins cannot bind to the catalytic site of the ribosome in this area (specifically the peptidyl transferase center, or PTC). [15] The SSU rRNA subtypes decode mRNA in its decoding center (DC). [16]
Initiation of translation in bacteria involves the assembly of the components of the translation system, which are: the two ribosomal subunits (50S and 30S subunits); the mature mRNA to be translated; the tRNA charged with N-formylmethionine (the first amino acid in the nascent peptide); guanosine triphosphate (GTP) as a source of energy, and the three prokaryotic initiation factors IF1, IF2 ...
This region is called the core promoter because of its essential role in transcription initiation. [ 12 ] [ 13 ] Different classes of sequence elements are found in the promoters. For example, the TATA box is the highly conserved DNA recognition sequence for the TATA box binding protein, TBP , whose binding initiates transcription complex ...
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