Structural basis for the recognition of K48-linked Ub chain by proteasomal receptor Rpn13.

ABSTRACT: The interaction between K48-linked ubiquitin (Ub) chain and Rpn13 is important for proteasomal degradation of ubiquitinated substrate proteins. Only the complex structure between the N-terminal domain of Rpn13 (Rpn13^NTD) and Ub monomer has been characterized, while it remains unclear how Rpn13 specifically recognizes K48-linked Ub chain. Using single-molecule FRET, here we show that K48-linked diubiquitin (K48-diUb) fluctuates among distinct conformational states, and a preexisting compact state is selectively enriched by Rpn13^NTD. The same binding mode is observed for full-length Rpn13 and longer K48-linked Ub chain. Using solution NMR spectroscopy, we have determined the complex structure between Rpn13^NTD and K48-diUb. In this structure, Rpn13^NTD

SUBMITTER: Liu Z 

PROVIDER: S-EPMC6443662 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature