Abstract
HHR23A, a protein implicated in nucleotide excision repair, belongs to a class of proteins containing both a ubiquitin-like (Ubl) domain and one or more ubiquitin-associated (UBA) domains, suggesting a role in the ubiquitin-proteasome pathway as well. The Ubl domain binds with high affinity to the second ubiquitin-interacting motif (UIM) of the S5a subunit of the proteasome. Here we present the solution structures of the HHR23A Ubl domain, the second UIM of S5a (UIM-2), and the Ubl:S5a-UIM-2 complex. The HHR23A Ubl domain is structurally similar to ubiquitin. The S5a UIM forms an alpha-helix with an unexpected hairpin loop that contributes to the binding interface with Ubl. The molecular determinants of the Ubl-proteasome interaction are revealed by analysis of the structures, chemical shift mapping, mutant binding studies and sequence conservation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.