RNA polymerasemedical dictionary

<enzyme>

<molecular biology> An enzyme that polymerise ribonucleotides in accordance with the information present in DNA.

Prokaryotes have a single enzyme for the three RNA types that is subject to stringent regulatory mechanisms. Eukaryotes have type I that synthesises all rRNA except the 5S component, type II that synthesises mRNA and hnRNA and type III that synthesises tRNA and the 5S component of rRNA.

(23 Aug 1998)