RPN13_C is a family of all-helical domains that forms the binding-surface for the proteasome-ubiquitn-receptor protein Rpn13 to UCH37, one of the three de-ubiquitinating enzymes of the proteasome [1,2].

1: Proteasome recruitment and activation of the Uch37 deubiquitinating enzyme by Adrm1. Yao T, Song L, Xu W, DeMartino GN, Florens L, Swanson SK, Washburn MP, Conaway RC, Conaway JW, Cohen RE; Nat Cell Biol. 2006;8:994-1002. PMID:16906146

2: Structure of proteasome ubiquitin receptor hRpn13 and its activation by the scaffolding protein hRpn2. Chen X, Lee BH, Finley D, Walters KJ; Mol Cell. 2010;38:404-415. PMID:20471946