polymerase Any enzyme that catalyses the elongation of a polymeric molecule. RNA polymerases (types I to III) catalyse the synthesis of RNA using as a template either an existing DNA strand (DNA-dependent RNA polymerase) or an RNA strand. Type I is responsible for the synthesis of ribosomal RNA, type II for messenger RNA synthesis (see transcription), and type III for transfer RNA synthesis. DNA polymerases catalyse the elongation of a new DNA strand during DNA replication, using an existing DNA strand as template. RNA-directed DNA polymerase is more usually known as reverse transcriptase.

polymerase An enzyme that catalyses the replication and repair of nucleic acids.

polymerase An enzyme that catalyses the replication and repair of nucleic acids.