3BLI

Crystal structure of the catalytic domain of LiCMS in complexed with pyruvate and acetyl-CoA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.229 

Starting Model: experimental
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This is version 2.0 of the entry. See complete history


Literature

Molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from Leptospira interrogans

Ma, J.Zhang, P.Zhang, Z.Zha, M.Xu, H.Zhao, G.Ding, J.

(2008) Biochem J 415: 45-56

  • DOI: https://doi.org/10.1042/BJ20080242
  • Primary Citation of Related Structures:  
    3BLE, 3BLF, 3BLI

  • PubMed Abstract: 

    Leptospira interrogans is the causative agent for leptospirosis, a zoonotic disease of global importance. In contrast with most other micro-organisms, L. interrogans employs a pyruvate pathway to synthesize isoleucine and LiCMS (L. interrogans citramalate synthase) catalyses the first reaction of the pathway which converts pyruvate and acetyl-CoA into citramalate, thus making it an attractive target for the development of antibacterial agents. We report here the crystal structures of the catalytic domain of LiCMS and its complexes with substrates, and kinetic and mutagenesis studies of LiCMS, which together reveal the molecular basis of the high substrate specificity and the catalytic mechanism of LiCMS. The catalytic domain consists of a TIM barrel flanked by an extended C-terminal region. It forms a homodimer in the crystal structure, and the active site is located at the centre of the TIM barrel near the C-terminal ends of the beta-strands and is composed of conserved residues of the beta-strands of one subunit and the C-terminal region of the other. The substrate specificity of LiCMS towards pyruvate against other alpha-oxo acids is dictated primarily by residues Leu(81), Leu(104) and Tyr(144), which form a hydrophobic pocket to accommodate the C(2)-methyl group of pyruvate. The catalysis follows the typical aldol condensation reaction, in which Glu(146) functions as a catalytic base to activate the methyl group of acetyl-CoA to form an enolated acetyl-CoA intermediate and Arg(16) as a general acid to stabilize the intermediate.


  • Organizational Affiliation

    Laboratory of Microbial Molecular Physiology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Feng-Lin Road, Shanghai 200032, China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Citramalate synthase from Leptospira interrogans337Leptospira interrogansMutation(s): 0 
Gene Names: cimA
EC: 2.3.3.13
UniProt
Find proteins for Q8F3Q1 (Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai (strain 56601))
Explore Q8F3Q1 
Go to UniProtKB:  Q8F3Q1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8F3Q1
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.229 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.99α = 90
b = 84.99β = 90
c = 115.73γ = 120
Software Package:
Software NamePurpose
PHASERphasing
CNSrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
CrystalCleardata reduction
CrystalCleardata 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: 2008-11-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 2.0: 2023-11-15
    Changes: Atomic model, Data collection, Derived calculations