5LZP

Binding of the C-terminal GQYL motif of the bacterial proteasome activator Bpa to the 20S proteasome

Summary for 5LZP

• Entry DOI: 10.2210/pdb5lzp/pdb
• EMDB information: 4128
• Descriptor: Proteasome subunit alpha, Bacterial proteasome activator, Proteasome subunit beta (3 entities in total)
• Functional Keywords: proteasome, proteasome activator, protein degradation, complex, hydrolase
• Biological source: Mycobacterium tuberculosis H37Rv; More
• Total number of polymer chains: 35
• Total formula weight: 859299.44

Authors

Bolten, M.,Delley, C.L.,Leibundgut, M.,Boehringer, D.,Ban, N.,Weber-Ban, E. (deposition date: 2016-09-30, release date: 2016-11-23, Last modification date: 2024-05-15)

Primary citation

Bolten, M.,Delley, C.L.,Leibundgut, M.,Boehringer, D.,Ban, N.,Weber-Ban, E.
Structural Analysis of the Bacterial Proteasome Activator Bpa in Complex with the 20S Proteasome.
Structure, 24:2138-2151, 2016

PubMed Abstract: Mycobacterium tuberculosis harbors proteasomes that recruit substrates for degradation through an ubiquitin-like modification pathway. Recently, a non-ATPase activator termed Bpa (bacterial proteasome activator) was shown to support an alternate proteasomal degradation pathway. Here, we present the cryo-electron microscopy (cryo-EM) structure of Bpa in complex with the 20S core particle (CP). For docking into the cryo-EM density, we solved the X-ray structure of Bpa, showing that it forms tight four-helix bundles arranged into a 12-membered ring with a 40 Å wide central pore and the C-terminal helix of each protomer protruding from the ring. The Bpa model was fitted into the cryo-EM map of the Bpa-CP complex, revealing its architecture and striking symmetry mismatch. The Bpa-CP interface was resolved to 3.5 Å, showing the interactions between the C-terminal GQYL motif of Bpa and the proteasome α-rings. This docking mode is related to the one observed for eukaryotic activators with features specific to the bacterial complex.

PubMed: 27839949
DOI: 10.1016/j.str.2016.10.008

Experimental method

ELECTRON MICROSCOPY (3.5 Å)