Crystal structure of Mycobacterium smegmatis alpha-ketoglutarate decarboxylase homodimer (orthorhombic form)

Experimental Data Snapshot

  • Resolution: 2.74 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 

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Functional Plasticity and Allosteric Regulation of Alpha-Ketoglutarate Decarboxylase in Central Mycobacterial Metabolism.

Wagner, T.Bellinzoni, M.Wehenkel, A.M.O'Hare, H.M.Alzari, P.M.

(2011) Chem Biol 18: 1011

  • DOI: https://doi.org/10.1016/j.chembiol.2011.06.004
  • Primary Citation of Related Structures:  
    2XT6, 2XTA, 2Y0P, 2YIC, 2YID

  • PubMed Abstract: 

    The α-ketoglutarate dehydrogenase (KDH) complex is a major regulatory point of aerobic energy metabolism. Mycobacterium tuberculosis was reported to lack KDH activity, and the putative KDH E1o component, α-ketoglutarate decarboxylase (KGD), was instead assigned as a decarboxylase or carboligase. Here, we show that this protein does in fact sustain KDH activity, as well as the additional two reactions, and these multifunctional properties are shared by the Escherichia coli homolog, SucA. We also show that the mycobacterial enzyme is finely regulated by an additional acyltransferase-like domain and by the action of acetyl-CoA, a powerful allosteric activator able to enhance the concerted protein motions observed during catalysis. Our results uncover the functional plasticity of a crucial node in bacterial metabolism, which may be important for M. tuberculosis during host infection.

  • Organizational Affiliation

    Institut Pasteur, Unité de Biochimie Structurale (CNRS URA 2185), 25 rue du Dr. Roux, 75724 Paris, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
1,113Mycolicibacterium smegmatis MC2 155Mutation(s): 0 
Find proteins for A0R2B1 (Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155))
Explore A0R2B1 
Go to UniProtKB:  A0R2B1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0R2B1
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.74 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 151.99α = 90
b = 247.72β = 90
c = 79.98γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-06-15
    Type: Initial release
  • Version 1.1: 2011-10-12
    Changes: Database references, Version format compliance
  • Version 1.2: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description