DNA-Directed RNA Polymerases

**Definition:** Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).

**Tree numbers:** - D08.811.913.696.445.735.270

**Synonyms:** - DNA-Dependent RNA Polymerases - RNA Polymerase - RNA Polymerases - Transcriptases - DNA-Directed RNA Polymerase