Homologous Superfamily

DNA-directed RNA polymerase, insert domain superfamily (IPR036643)

Short name: RNApol_insert_sf

Overlapping entries


RNA polymerase (RNAP) II, which is responsible for all mRNA synthesis in eukaryotes, consists of 12 subunits. Subunits Rpb3 and Rpb11 form a heterodimer that is functionally analogous to the archaeal RNAP D/L heterodimer, and to the prokaryotic RNAP alpha (RpoA) subunit homodimer. In each case, they play a key role in RNAP assembly by forming a platform on which the catalytic subunits (eukaryotic Rpb1/Rpb2, and prokaryotic beta/beta') can interact [PMID: 11453250].

The dimerisation domains differ between the different subunit families. In eukaryotic Rpb3, archaeal D and bacterial RpoA subunits (IPR011263), the dimerisation domain is comprised of a central insert domain, which interrupts an Rpb11-like domain (IPR036603), dividing it into two halves [PMID: 9657722]. In eukaryotic Rpb11 and archaeal L subunits, the insert domain is lacking, leaving the Rpb11-like domain intact and contiguous.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.