RNA Polymerase

Synonyms

DNA (or RNA-)-dependent RNA polymerase; RNA replicase

Definition

RNA polymerase is an enzyme which catalyzes the addition of a ribonucleoside triphosphate to the 3′ – end of a RNA strand using a template. The systematic name of this enzymatic activity is nucleoside triphosphate-RNA nucleotidyltransferase, and the catalyzed reaction can be represented as

$$ \mathrm{nucleoside}\ \mathrm{triphosphate}+{\mathrm{RNA}}_n=\mathrm{diphosphate}+{{\mathrm{RNA}}_n}_{+1} $$

DNA-directed RNA polymerases (EC 2.7.7.6) use DNA templates, whereas RNA-directed RNA polymerases (EC 2.7.7.48) use RNA templates. These enzymes can initiate a chain de novo. In eukaryotes different RNA polymerases participate in the transcription of the diverse types of RNA. In prokaryotes, a multimeric RNA polymerase performs the transcription of the different classes of RNA.

History

Sam Weiss, Audrey Stevens, and Jerard Hurwitz discovered independently the DNA-dependent RNA polymerase activity in 1960.

See Also

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