6zzn
From Proteopedia
Crystal structure of the cubic catalytic core of the Mycobacterium tuberculosis branched-chain alphaketoacid acyltransferase component (E2b).
Structural highlights
FunctionBKDC_MYCTU Component of the branched-chain alpha-ketoacid dehydrogenase (BCKADH) complex, that catalyzes the overall conversion of branched-chain alpha-ketoacids to acyl-CoA and CO(2).[1] Publication Abstract from PubMedalpha-oxoacid dehydrogenase complexes are large, tripartite enzymatic machineries carrying out key reactions in central metabolism. Extremely conserved across the tree of life, they have been, so far, all considered to be structured around a high-molecular weight hollow core, consisting of up to 60 subunits of the acyltransferase component. We provide here evidence that Actinobacteria break the rule by possessing an acetyltranferase component reduced to its minimally active, trimeric unit, characterized by a unique C-terminal helix bearing an actinobacterial specific insertion that precludes larger protein oligomerization. This particular feature, together with the presence of an odhA gene coding for both the decarboxylase and the acyltransferase domains on the same polypetide, is spread over Actinobacteria and reflects the association of PDH and ODH into a single physical complex. Considering the central role of the pyruvate and 2-oxoglutarate nodes in central metabolism, our findings pave the way to both therapeutic and metabolic engineering applications. Actinobacteria challenge the paradigm: A unique protein architecture for a well-known, central metabolic complex.,Bruch EM, Vilela P, Yang L, Boyko A, Lexa-Sapart N, Raynal B, Alzari PM, Bellinzoni M Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). pii: 2112107118. doi:, 10.1073/pnas.2112107118. PMID:34819376[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
