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PDBsum entry 2f8h
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References listed in PDB file
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Key reference
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Title
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Structure of a novel n-Acetyl-L-Citrulline deacetylase from xanthomonas campestris.
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Authors
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D.Shi,
X.Yu,
L.Roth,
M.Tuchman,
N.M.Allewell.
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Ref.
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Biophys Chem, 2007,
126,
86-93.
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PubMed id
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Abstract
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The structure of a novel acetylcitrulline deacetylase from the plant pathogen
Xanthomonas campestris has been solved by multiple-wavelength anomalous
dispersion (MAD) using crystals grown from selenomethionine-substituted protein
and refined at 1.75 A resolution. The asymmetric unit of the crystal contains
one monomer consisting of two domains, a catalytic domain and a dimerization
domain. The catalytic domain is able to bind a single Co(II) ion at the active
site with no change in conformation. The dimerization domain forms an interface
between two monomers related by a crystallographic two-fold symmetry axis. The
interface is maintained by hydrophobic interactions between helices and hydrogen
bonding between two beta strands that form a continuous beta sheet across the
dimer interface. Because the dimers are also related by two-fold
crystallographic axes, they pack together across the crystal via the
dimerization domain, suggesting that higher order oligomers may form in
solution. The polypeptide fold of the monomer is similar to the fold of
Pseudomonas sp. carboxypeptidase G2 and Neisseria meningitidis succinyl
diaminopimelate desuccinylase. Structural comparison among these enzymes allowed
modeling of substrate binding and suggests a possible catalytic mechanism, in
which Glu130 functions as a bifunctional general acid-base catalyst and the
metal ion polarizes the carbonyl of the acetyl group.
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