9B78

Mycobacterium tuberculosis CoaX Homohexamer

Summary for 9B78

• Entry DOI: 10.2210/pdb9b78/pdb
• EMDB information: 44303
• Descriptor: Type III pantothenate kinase (1 entity in total)
• Functional Keywords: pantothenate kinase isoform, cytosolic protein
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 6
• Total formula weight: 176050.07

Authors

Chen, J.,Ekiert, D.C.,Bhabha, G. (deposition date: 2024-03-27, release date: 2024-11-13, Last modification date: 2024-12-11)

Primary citation

Kahne, S.C.,Yoo, J.H.,Chen, J.,Nakedi, K.,Iyer, L.M.,Putzel, G.,Samhadaneh, N.M.,Pironti, A.,Aravind, L.,Ekiert, D.C.,Bhabha, G.,Rhee, K.Y.,Darwin, K.H.
Identification of a depupylation regulator for an essential enzyme in Mycobacterium tuberculosis.
Proc.Natl.Acad.Sci.USA, 121:e2407239121-e2407239121, 2024

PubMed Abstract: In , proteins that are posttranslationally modified with a prokaryotic ubiquitin-like protein (Pup) can be degraded by bacterial proteasomes. A single Pup-ligase and depupylase shape the pupylome, but the mechanisms regulating their substrate specificity are incompletely understood. Here, we identified a depupylation regulator, a protein called CoaX, through its copurification with the depupylase Dop. CoaX is a pseudopantothenate kinase that showed evidence of binding to pantothenate, an essential nutrient synthesizes, but not its phosphorylation. In a ∆ mutant, pantothenate synthesis enzymes including PanB, a substrate of the Pup-proteasome system (PPS), were more abundant than in the parental strain. In vitro, CoaX specifically accelerated depupylation of Pup~PanB, while addition of pantothenate inhibited this reaction. In culture, media supplementation with pantothenate decreased PanB levels, which required CoaX. Collectively, we propose CoaX regulates PanB abundance in response to pantothenate levels by modulating its vulnerability to proteolysis by proteasomes.

PubMed: 39585979
DOI: 10.1073/pnas.2407239121

Experimental method

ELECTRON MICROSCOPY (2.59 Å)