MPN domain of 26S proteasome non-ATPase regulatory subunit 7
26S proteasome non-ATPase regulatory subunit 7 (PSMD7; also known as 26S proteasome regulatory subunit RPN8, 26S proteasome regulatory subunit S12, Mov34 protein homolog, or proteasome subunit p40) is one of the non-ATPase subunits (Rpns) that are involved in recognizing substrates and deubiquitylating them before unfolding and degradation. Rpns are part of the regulatory particle (RP) of the 26S proteasome holocomplex. RPN8 forms a dimer with deubiquitylating enzyme (DUB) Rpn11, which plays a role in projecting the active site of Rpn11. RPN8 shows a typical MPN metalloprotease fold, but lacks the canonical JAMM motif, and therefore does not show catalytic isopeptidase activity.