Structural analysis of mycobacterial branched chain aminotransferase- implications for inhibitor design

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.190 

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Structural analysis of mycobacterial branched-chain aminotransferase: implications for inhibitor design.

Castell, A.Mille, C.Unge, T.

(2010) Acta Crystallogr D Biol Crystallogr 66: 549-557

  • DOI: https://doi.org/10.1107/S0907444910004877
  • Primary Citation of Related Structures:  
    3DTF, 3JZ6

  • PubMed Abstract: 

    The branched-chain aminotransferase (BCAT) of Mycobacterium tuberculosis has been characterized as being essential to the survival of the bacterium. The enzyme is pyridoxal 5'-phosphate-dependent and belongs to the aminotransferase IIIa subfamily, to which the human BCATs also belong. The overall sequence similarity is high within the subfamily and the sequence identity among the active-site residues is high. In order to identify structurally unique features of M. tuberculosis BCAT, X-ray structural and functional analyses of the closely related BCAT from M. smegmatis were carried out. The crystal structures include the apo form at 2.2 A resolution and a 1.9 A structure of the holo form cocrystallized with the inhibitor O-benzylhydroxylamine (Obe). The analyses highlighted the active-site residues Tyr209 and Gly243 as being structurally unique characteristics of the mycobacterial BCATs relative to the human BCATs. The inhibitory activities of Obe and ammonium sulfate were verified in an inhibition assay. Modelling of the inhibitor Obe in the substrate pocket indicated potential for the design of a mycobacterial-specific inhibitor.

  • Organizational Affiliation

    Department of Cell and Molecular Biology, Uppsala University, BMC, SE-751 24 Uppsala, Sweden.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Branched-chain amino acid aminotransferase
A, B
372Mycolicibacterium smegmatis MC2 155Mutation(s): 0 
Gene Names: ilvEMSMEG_4276
Find proteins for A0R066 (Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155))
Explore A0R066 
Go to UniProtKB:  A0R066
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0R066
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.190 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.9α = 90
b = 88.05β = 105.6
c = 73.17γ = 90
Software Package:
Software NamePurpose
DNAdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2012-04-11
    Changes: Database references
  • Version 1.3: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description