Archaeal RNA polymerase (RNAP), like bacterial RNAP, is a large multi-subunit complex responsible for the synthesis of all RNAs in the cell. The relative positioning of the RNAP core is highly conserved between archaeal RNAP and the three classes of eukaryotic RNAPs. In archaea, the largest subunit is split into two polypeptides, A' and A'', which are encoded by separate genes in an operon. Sequence alignments reveal that the archaeal A'' subunit corresponds to the C-terminal one-third of the RNAPII largest subunit (Rpb1). In subunit A'', several loops in the jaw domain are shorter. The RNAPII Rpb1 interacts with the second-largest subunit (Rpb2) to form the DNA entry and RNA exit channels in addition to the catalytic center of RNA synthesis.
Feature 1:Rpb1_C (A") - Rpb1_N (A') interaction site
Evidence:
Comment:The A' and A" complex of archaeal RNAP is equivalent to the largest subunit of eukaryotic and bacterial RNAPs. The A' and A" subunits correspond to the N-terminal two-thirds and the C-terminal one-third, respectively, of RNAPII Rpb1.
Structure:2PMZ; Interface between the A" (2PMZ_C) and A' (2PMZ_A) subunits of Sulfolobus solfataricus RNAP; defined at 3.5A contacts.
Jiyao W et al.(2023). "The conserved domain database in 2023.",