PMID- 11748244
OWN - NLM
STAT- MEDLINE
DCOM- 20020415
LR  - 20131121
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 277
IP  - 10
DP  - 2002 Mar 8
TI  - The structure of 3-methylaspartase from Clostridium tetanomorphum functions via
      the common enolase chemical step.
PG  - 8306-11
AB  - 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.
FAU - Asuncion, Miryam
AU  - Asuncion M
AD  - The Centre for Biomolecular Sciences, The University, St. Andrews, Scotland,
      United Kingdom KY16 9ST.
FAU - Blankenfeldt, Wulf
AU  - Blankenfeldt W
FAU - Barlow, John N
AU  - Barlow JN
FAU - Gani, David
AU  - Gani D
FAU - Naismith, James H
AU  - Naismith JH
LA  - eng
SI  - PDB/1KCZ
SI  - PDB/1KD0
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20011217
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Carboxylic Acids)
RN  - 0 (Protons)
RN  - 2955-50-2 (3-methylaspartic acid)
RN  - 30KYC7MIAI (Aspartic Acid)
RN  - EC 4.2.1.11 (Phosphopyruvate Hydratase)
RN  - EC 4.3.1.- (Ammonia-Lyases)
RN  - EC 4.3.1.2 (methylaspartate ammonia-lyase)
RN  - K3Z4F929H6 (Lysine)
SB  - IM
MH  - Amino Acid Sequence
MH  - Ammonia-Lyases/*chemistry/*metabolism
MH  - Aspartic Acid/*analogs & derivatives/*chemistry
MH  - Binding Sites
MH  - Carboxylic Acids/chemistry
MH  - Catalysis
MH  - Clostridium/*chemistry
MH  - Dimerization
MH  - Escherichia coli/metabolism
MH  - Lysine/chemistry
MH  - Models, Chemical
MH  - Models, Molecular
MH  - Molecular Sequence Data
MH  - Phosphopyruvate Hydratase/*chemistry/metabolism
MH  - Protein Binding
MH  - Protein Conformation
MH  - Protein Structure, Secondary
MH  - Protein Structure, Tertiary
MH  - Protons
MH  - Sequence Homology, Amino Acid
EDAT- 2001/12/19 10:00
MHDA- 2002/04/16 10:01
CRDT- 2001/12/19 10:00
PHST- 2001/12/19 10:00 [pubmed]
PHST- 2002/04/16 10:01 [medline]
PHST- 2001/12/19 10:00 [entrez]
AID - 10.1074/jbc.M111180200 [doi]
AID - M111180200 [pii]
PST - ppublish
SO  - J Biol Chem. 2002 Mar 8;277(10):8306-11. doi: 10.1074/jbc.M111180200. Epub 2001
      Dec 17.