6J2X

Yeast proteasome in resting state (C1-a)

This is a non-PDB format compatible entry.

Summary for 6J2X

• Entry DOI: 10.2210/pdb6j2x/pdb
• EMDB information: 9772
• Descriptor: Proteasome subunit beta type-1, Proteasome subunit alpha type-3, Proteasome subunit alpha type-4, ... (33 entities in total)
• Functional Keywords: proteasome, k48-ub4, ub-bound, cryo-em, hydrolase
• Biological source: Saccharomyces cerevisiae S288c (Baker's yeast); More
• Total number of polymer chains: 47
• Total formula weight: 1692659.85

Authors

Cong, Y. (deposition date: 2019-01-03, release date: 2019-03-13, Last modification date: 2019-11-06)

Primary citation

Ding, Z.,Xu, C.,Sahu, I.,Wang, Y.,Fu, Z.,Huang, M.,Wong, C.C.L.,Glickman, M.H.,Cong, Y.
Structural Snapshots of 26S Proteasome Reveal Tetraubiquitin-Induced Conformations.
Mol. Cell, 73:1150-, 2019

PubMed Abstract: The 26S proteasome is the ATP-dependent protease responsible for regulating the proteome of eukaryotic cells through degradation of mainly ubiquitin-tagged substrates. In order to understand how proteasome responds to ubiquitin signal, we resolved an ensemble of cryo-EM structures of proteasome in the presence of K48-Ub, with three of them resolved at near-atomic resolution. We identified a conformation with stabilized ubiquitin receptors and a previously unreported orientation of the lid, assigned as a Ub-accepted state C1-b. We determined another structure C3-b with localized K48-Ub to the toroid region of Rpn1, assigned as a substrate-processing state. Our structures indicate that tetraUb induced conformational changes in proteasome could initiate substrate degradation. We also propose a CP gate-opening mechanism involving the propagation of the motion of the lid to the gate through the Rpn6-α2 interaction. Our results enabled us to put forward a model of a functional cycle for proteasomes induced by tetraUb and nucleotide.

PubMed: 30792173
DOI: 10.1016/j.molcel.2019.01.018

Experimental method

ELECTRON MICROSCOPY (3.8 Å)