1KCZ

Crystal Structure of beta-methylaspartase from Clostridium tetanomorphum. Mg-complex.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.175 
  • R-Value Work: 0.135 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The structure of 3-methylaspartase from Clostridium tetanomorphum functions via the common enolase chemical step.

Asuncion, M.Blankenfeldt, W.Barlow, J.N.Gani, D.Naismith, J.H.

(2002) J.Biol.Chem. 277: 8306-8311

  • DOI: 10.1074/jbc.M111180200
  • Primary Citation of Related Structures:  1KD0

  • PubMed Abstract: 
  • Methylaspartate ammonia-lyase (3-methylaspartase, MAL; EC ) catalyzes the reversible anti elimination of ammonia from L-threo-(2S,3S)-3-methylaspartic acid to give mesaconic acid. This reaction lies on the main catabolic pathway for glutamate in Clos ...

    Methylaspartate ammonia-lyase (3-methylaspartase, MAL; EC ) catalyzes the reversible anti elimination of ammonia from L-threo-(2S,3S)-3-methylaspartic acid to give mesaconic acid. This reaction lies on the main catabolic pathway for glutamate in Clostridium tetanomorphum. MAL requires monovalent and divalent cation cofactors for full catalytic activity. The enzyme has attracted interest because of its potential use as a biocatalyst. The structure of C. tetanomorphum MAL has been solved to 1.9-A resolution by the single-wavelength anomalous diffraction method. A divalent metal ion complex of the protein has also been determined. MAL is a homodimer with each monomer consisting of two domains. One is an alpha/beta-barrel, and the other smaller domain is mainly beta-strands. The smaller domain partially occludes the C terminus of the barrel and forms a large cleft. The structure identifies MAL as belonging to the enolase superfamily of enzymes. The metal ion site is located in a large cleft between the domains. Potential active site residues have been identified based on a combination of their proximity to a metal ion site, molecular modeling, and sequence homology. In common with all members of the enolase superfamily, the carboxylic acid of the substrate is co-ordinated by the metal ions, and a proton adjacent to a carboxylic acid group of the substrate is abstracted by a base. In MAL, it appears that Lys(331) removes the alpha-proton of methylaspartic acid. This motif is the defining mechanistic characteristic of the enolase superfamily of which all have a common fold. The degree of structural conservation is remarkable given only four residues are absolutely conserved.


    Related Citations: 
    • Overexpression, purification, crystallization and data collection of 3-methylaspartase from Clostridium tetanomorphum
      Asuncion, M.,Barlow, J.N.,Pollard, J.,Staines, A.G.,McMahon, S.A.,Blankenfeldt, W.,Gani, D.,Naismith, J.H.
      (2001) Acta Crystallogr.,Sect.D 57: 731


    Organizational Affiliation

    The Centre for Biomolecular Sciences, The University, St. Andrews, Scotland, United Kingdom KY16 9ST.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
beta-methylaspartase
A, B
413Clostridium tetanomorphumEC: 4.3.1.2
Find proteins for Q05514 (Clostridium tetanomorphum)
Go to UniProtKB:  Q05514
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EDO
Query on EDO

Download SDF File 
Download CCD File 
A, B
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
OCS
Query on OCS
A, B
L-PEPTIDE LINKINGC3 H7 N O5 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.175 
  • R-Value Work: 0.135 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 67.016α = 90.00
b = 108.783β = 90.00
c = 109.557γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
SnBphasing
SHAKE-N-BAKEphasing
MOSFLMdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-12-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Refinement description, Version format compliance