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PDBsum entry 1v7x
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Chitobiose phosphorylase from vibrio proteolyticus, A member of glycosyl transferase family 36, Has a clan gh-L-Like (alpha/alpha)(6) barrel fold.
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Authors
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M.Hidaka,
Y.Honda,
M.Kitaoka,
S.Nirasawa,
K.Hayashi,
T.Wakagi,
H.Shoun,
S.Fushinobu.
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Ref.
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Structure, 2004,
12,
937-947.
[DOI no: ]
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PubMed id
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Abstract
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Vibrio proteolyticus chitobiose phosphorylase (ChBP) belongs to glycosyl
transferase family 36 (GT-36), and catalyzes the reversible phosphorolysis of
chitobiose into alpha-GlcNAc-1-phosphate and GlcNAc with inversion of the
anomeric configuration. As the first known structures of a GT-36 enzyme, we
determined the crystal structure of ChBP in a ternary complex with GlcNAc and
SO(4). It is also the first structures of an inverting phosphorolytic enzyme in
a complex with a sugar and a sulfate ion, and reveals a pseudo-ternary complex
structure of enzyme-sugar-phosphate. ChBP comprises a beta sandwich domain and
an (alpha/alpha)(6) barrel domain, constituting a distinctive structure among GT
families. Instead, it shows significant structural similarity with glycoside
hydrolase (GH) enzymes, glucoamylases (GH-15), and maltose phosphorylase (GH-65)
in clan GH-L. The structural similarity reported here, together with distant
sequence similarities between ChBP and GHs, led to the reclassification of
family GT-36 into a novel GH family, namely GH-94.
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Figure 1.
Figure 1. Ribbon Diagrams of ChBP and Related Structures(A)
Overall structure of the ChBP monomer (GlcNAc complex) shown as
a ribbon model (N-terminal domain, blue; linker helices, green;
a-helical barrel domain, yellow; C-terminal domain, red). The
bound GlcNAc molecules (red), P394, and I417 (yellow) are shown
as a ball-and-stick model, and the chloride (green) and calcium
(black) ions are shown as a sphere. Residues between P394 and
I417 are not included in the final model structure.(B) Ribbon
diagram presentation of the ChBP dimer. The subunits are located
around the crystallographic 2-fold axis. One subunit is colored
as in (A), and the other one is colored white.(C) A ribbon
diagram of bGA (1LF9; GH-15). Bacterial and archaeal
glucoamylases comprise an N-terminal b sandwich domain (blue),
linker helices (green), and an a-helical barrel domain (yellow),
whereas fungal glucoamylases comprise only an a-helical barrel
domain. The bound acarbose molecule (red) is shown as a
ball-and-stick model.(D) A ribbon diagram of MalP (1H54; GH-65).
The bound phosphate ion is shown as a ball-and-stick model. The
domain constitution is identical with that of ChBP and each
domain is colored as in (A).
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The above figure is
reprinted
by permission from Cell Press:
Structure
(2004,
12,
937-947)
copyright 2004.
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Secondary reference #1
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Title
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Reaction mechanism of chitobiose phosphorylase from vibrio proteolyticus: identification of family 36 glycosyltransferase in vibrio.
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Authors
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Y.Honda,
M.Kitaoka,
K.Hayashi.
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Ref.
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Biochem J, 2004,
377,
225-232.
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PubMed id
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