Understanding the Mechanism of RNA Polymerase: Unraveling the Transcription Process

Overview

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• Source: Microbioz India


• Date: 06 Nov,2023

RNA polymerase is an enzyme that is in charge of transcription, which is the process of producing RNA from a DNA template.

The RNA polymerase mechanism can be summarized in many main steps:

Initiation:

RNA polymerase has a knack for finding its way to the promoter region in a specific part of DNA. When it does this, it triggers the start of transcription. Eukaryotic cells have many differences when compared to prokaryotes. One main one is that they don’t only have a single kind of RNA polymerase, they have several instead. To locate the beginning of transcription there’s an enzyme in RNA polymerase that uses consensus sequences found in the promoter region.

Elongation:

RNA polymerase unravels the DNA double helix within the transcription bubble subsequent to its attachment to the promoter. After reading the DNA template strand, it adds complementary RNA nucleotides to create an RNA strand. The enzyme lengthens the RNA strand in a5′ to 3′ direction as it travels along the DNA, unwinding it.

Termination:

Rho-dependent and Rho-independent termination are the two most prevalent termination mechanisms in prokaryotes. When a certain RNA sequence in the transcript develops a hairpin structure and is followed by a string of uracil residues, it is known as a rho-independent termination. As a result, RNA polymerase separates. Eukaryotes have a more complicated termination process that includes RNA breakage and polyadenylation.

Post-transcriptional processing:

In eukaryotes, the freshly created RNA, known as pre-mRNA, is modified in a number of ways, for as by adding a 3′ poly-A tail and a 5′ cap. Exons, or coding sections, are joined together after introns, or non-coding regions, are cut out. The end product is mature mRNA.

Deciphering the process by which genetic information is transferred from DNA into functional RNA molecules—which serve as templates for protein synthesis in cells—needs an understanding of the mechanism of RNA polymerase.