What is RNA polymerase?

RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, during the transcription process.

The RNA polymerase enzyme exists as a large protein complex made up of about multiple subunits that are used as catalytic promoters and for the assembly of proteins.

RNA polymerase is found in all living organisms including several viruses but the type and number vary across taxa. Prokaryotes – bacteria, viruses and archaea - contain a single type of RNA polymerase that synthesizes all RNA subtypes. Eukaryotes - multicellular organisms - contain 5 distinct types of RNA polymerases, which perform different functions in the synthesis of different RNA molecules.

Although the transcriptional mechanism is fundamentally similar in both prokaryotes and eukaryotes, it is much more complex in eukaryotic cells.