5UN0

Crystal Structure of Mycobacterium Tuberculosis Proteasome-assembly chaperone homologue Rv2125

Summary for 5UN0

• Entry DOI: 10.2210/pdb5un0/pdb
• Descriptor: proteasome assembly chaperone 2 (PAC2) homologue Rv2125 (2 entities in total)
• Functional Keywords: activator, apoptosis
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 3
• Total formula weight: 82457.43

Authors

Bai, L.,Jastrab, J.B.,Hu, K.,Yu, H.,Darwin, K.H.,Li, H. (deposition date: 2017-01-30, release date: 2017-03-01, Last modification date: 2023-10-04)

Primary citation

Bai, L.,Jastrab, J.B.,Isasa, M.,Hu, K.,Yu, H.,Gygi, S.P.,Darwin, K.H.,Li, H.
Structural Analysis of Mycobacterium tuberculosis Homologues of the Eukaryotic Proteasome Assembly Chaperone 2 (PAC2).
J. Bacteriol., 199:-, 2017

PubMed Abstract: A previous bioinformatics analysis identified the proteins Rv2125 and Rv2714 as orthologs of the eukaryotic proteasome assembly chaperone 2 (PAC2). We set out to investigate whether Rv2125 or Rv2714 can function in proteasome assembly. We solved the crystal structure of Rv2125 at a resolution of 3.0 Å, which showed an overall fold similar to that of the PAC2 family proteins that include the archaeal PbaB and the yeast Pba1. However, Rv2125 and Rv2714 formed trimers, whereas PbaB forms tetramers and Pba1 dimerizes with Pba2. We also found that purified Rv2125 and Rv2714 could not bind to 20S core particles. Finally, proteomic analysis showed that the levels of known proteasome components and substrate proteins were not affected by disruption of Rv2125 in Our work suggests that Rv2125 does not participate in bacterial proteasome assembly or function. Although many bacteria do not encode proteasomes, not only uses proteasomes but also has evolved a posttranslational modification system called pupylation to deliver proteins to the proteasome. Proteasomes are essential for to cause lethal infections in animals; thus, determining how proteasomes are assembled may help identify new ways to combat tuberculosis. We solved the structure of a predicted proteasome assembly factor, Rv2125, and isolated a genetic Rv2125 mutant of Our structural, biochemical, and genetic studies indicate that Rv2125 and Rv2714 do not function as proteasome assembly chaperones and are unlikely to have roles in proteasome biology in mycobacteria.

PubMed: 28193903
DOI: 10.1128/JB.00846-16

Experimental method

X-RAY DIFFRACTION (3 Å)