Structural basis for the recognition and ubiquitylation of type-2 N-degron substrate by PRT1 plant N-recognin.

ABSTRACT: PROTEOLYSIS1 (PRT1), an N-recognin of Arabidopsis thaliana, recognizes the N-terminal aromatic hydrophobic residue (Tyr/Phe/Trp) of its substrates and ubiquitylates them for degradation by the ubiquitin-proteasome system. Herein, we report the structures of the ZZ domain of PRT1 (PRT1ZZ) in complex with bulky hydrophobic N-degron peptides. Unlike other ZZ domains, PRT1ZZ has an unusual binding site with two hydrophobic regions. The N-terminal aromatic residues of N-degrons interact with Ile333 and Phe352 in the flexible loops, which undergo a conformational change. Notably, we identify a third residue from the N-terminus of the substrate that participates in the hydrophobic network with PRT1ZZ. Moreover, AlphaFold prediction and biochemical assays revealed that the tandem RING1 and RING2 d

SUBMITTER: Yang WS 

PROVIDER: S-EPMC12370974 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature