Structure and function of a HECT domain ubiquitin-binding site.

ABSTRACT: The Rsp5 ubiquitin ligase contains a non-covalent binding site for ubiquitin within the amino-terminal lobe (N-lobe) of the HECT domain, and the X-ray crystal structure of the HECT-ubiquitin complex has been determined. Hydrophobic patch residues of ubiquitin (L8, I44, V70) were crucial for interaction with Rsp5, and amino-acid alterations at the Rsp5-binding interface resulted in defects in polyubiquitination. Our results support a model in which the N-lobe-binding site acts to localize and orient the distal end of the ubiquitin chain to promote conjugation of the next ubiquitin molecule.

SUBMITTER: Kim HC 

PROVIDER: S-EPMC3077248 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature