8U6Y

Preholo-Proteasome from Beta 3 D205 deletion

This is a non-PDB format compatible entry.

Summary for 8U6Y

• Entry DOI: 10.2210/pdb8u6y/pdb
• EMDB information: 41963
• Descriptor: Proteasome subunit alpha type-1, Proteasome subunit beta type-3, Proteasome subunit beta type-4, ... (17 entities in total)
• Functional Keywords: proteasome, core particle, hydrolase
• Biological source: Saccharomyces cerevisiae S288C; More
• Total number of polymer chains: 34
• Total formula weight: 919962.19

Authors

Walsh Jr., R.M.,Rawson, S.,Velez, B.,Blickling, M.,Razi, A.,Hanna, J. (deposition date: 2023-09-14, release date: 2024-04-17, Last modification date: 2024-10-16)

Primary citation

Velez, B.,Walsh Jr., R.M.,Rawson, S.,Razi, A.,Adams, L.,Perez, E.F.,Jiao, F.,Blickling, M.,Rajakumar, T.,Fung, D.,Huang, L.,Hanna, J.
Mechanism of autocatalytic activation during proteasome assembly.
Nat.Struct.Mol.Biol., 31:1167-1175, 2024

PubMed Abstract: Many large molecular machines are too elaborate to assemble spontaneously and are built through ordered pathways orchestrated by dedicated chaperones. During assembly of the core particle (CP) of the proteasome, where protein degradation occurs, its six active sites are simultaneously activated via cleavage of N-terminal propeptides. Such activation is autocatalytic and coupled to fusion of two half-CP intermediates, which protects cells by preventing activation until enclosure of the active sites within the CP interior. Here we uncover key mechanistic aspects of autocatalytic activation, which proceeds through alignment of the β5 and β2 catalytic triad residues, respectively, with these triads being misaligned before fusion. This mechanism contrasts with most other zymogens, in which catalytic centers are preformed. Our data also clarify the mechanism by which individual subunits can be added in a precise, temporally ordered manner. This work informs two decades-old mysteries in the proteasome field, with broader implications for protease biology and multisubunit complex assembly.

PubMed: 38600323
DOI: 10.1038/s41594-024-01262-1

Experimental method

ELECTRON MICROSCOPY (2.8 Å)