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Localization of the proteasomal ubiquitin receptors Rpn10 and Rpn13 by electron cryomicroscopy.

ABSTRACT: Two canonical subunits of the 26S proteasome, Rpn10 and Rpn13, function as ubiquitin (Ub) receptors. The mutual arrangement of these subunits--and all other non-ATPase subunits--in the regulatory particle is unknown. Using electron cryomicroscopy, we calculated difference maps between wild-type 26S proteasome from Saccharomyces cerevisiae and deletion mutants (rpn10?, rpn13?, and rpn10?rpn13?). These maps allowed us to localize the two Ub receptors unambiguously. Rpn10 and Rpn13 mapped to the apical part of the 26S proteasome, above the N-terminal coiled coils of the AAA-ATPase heterodimers Rpt4/Rpt5 and Rpt1/Rpt2, respectively. On the basis of the mutual positions of Rpn10 and Rpn13, we propose a model for polyubiquitin binding to the 26S proteasome.

SUBMITTER: Sakata E

PROVIDER: S-EPMC3277190 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Localization of the proteasomal ubiquitin receptors Rpn10 and Rpn13 by electron cryomicroscopy.

Sakata Eri E Bohn Stefan S Mihalache Oana O Kiss Petra P Beck Florian F Nagy Istvan I Nickell Stephan S Tanaka Keiji K Saeki Yasushi Y Förster Friedrich F Baumeister Wolfgang W

Proceedings of the National Academy of Sciences of the United States of America 20120103 5

Two canonical subunits of the 26S proteasome, Rpn10 and Rpn13, function as ubiquitin (Ub) receptors. The mutual arrangement of these subunits--and all other non-ATPase subunits--in the regulatory particle is unknown. Using electron cryomicroscopy, we calculated difference maps between wild-type 26S proteasome from Saccharomyces cerevisiae and deletion mutants (rpn10Δ, rpn13Δ, and rpn10Δrpn13Δ). These maps allowed us to localize the two Ub receptors unambiguously. Rpn10 and Rpn13 mapped to the ap ...[more]

PMID: 22215586

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