Largest subunit (Rpb1) of eukaryotic RNA polymerase II (RNAP II), N-terminal domain
The two largest subunits of RNA polymerase II (RNAP II), Rpb1 and Rpb2, form the active site, DNA entry channel and RNA exit channel. RNAP II is a large multi-subunit complex responsible for the synthesis of mRNA in eukaryotes. RNAP II consists of a 10-subunit core enzyme and a peripheral heterodimer of two subunits. Structure studies suggest that RNAP complexes from different organisms share a crab-claw-shape structure. In yeast, Rpb1 and Rpb2, each makes up one clamp, one jaw, and part of the cleft. Rpb1_N contains part of the active site, forms the head and core of the one clamp, and makes up the pore and funnel regions of RNAP II.
Comment:A complex active site region of DNA-dependent RNA polymerase mainly formed by Rpb1 and Rpb2 subunits, including Mg binding site, Bridge Helix, Switch and Funnel domains
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