InterPro domain: IPR040773

This is the N-terminal domain found in Rpn6 proteins (26S proteasome regulatory subunit). The 26S proteasome holocomplex consists of a 28-subunit barrel-shaped core particle (CP) in the centre capped at the top and bottom by 19-subunit regulatory particles (RPs). The CP forms the catalytic chamber and the RP is formed from two subcomplexes known as the lid and the base [ 1 ]. The lid comprises nine Rpn subunits in yeast (Rpn3/5/6/7/8/9/11/12/15) and the base comprises three Rpn subunits (Rpn1/2/13) and six ATPases (Rpt1-6) [ 2 ]. Phosphorylation of Rpn6 enhances proteasome ATPase activity and promotes the formation of doubly capped (30S) proteasome, hence accelerating the degradation of short-lived proteins [ 3 ].

1. Structural basis for dynamic regulation of the human 26S proteasome. Proc. Natl. Acad. Sci. U.S.A. 113, 12991-12996
2. Structure of an endogenous yeast 26S proteasome reveals two major conformational states. Proc. Natl. Acad. Sci. U.S.A. 113, 2642-7
3. Reversible phosphorylation of the 26S proteasome. Protein Cell 8, 255-272