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PDBsum entry 2j1e
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References listed in PDB file
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Key reference
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Title
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The interaction of a carbohydrate-Binding module from a clostridium perfringens n-Acetyl-Beta-Hexosaminidase with its carbohydrate receptor.
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Authors
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E.Ficko-Blean,
A.B.Boraston.
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Ref.
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J Biol Chem, 2006,
281,
37748-37757.
[DOI no: ]
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PubMed id
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Abstract
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Clostridium perfringens is a notable colonizer of the human gastrointestinal
tract. This bacterium is quite remarkable for a human pathogen by the number of
glycoside hydrolases found in its genome. The modularity of these enzymes is
striking as is the frequent occurrence of modules having amino acid sequence
identity with family 32 carbohydrate-binding modules (CBMs), often referred to
as F5/8 domains. Here we report the properties of family 32 CBMs from a C.
perfringens N-acetyl-beta-hexosaminidase. Macroarray, UV difference, and
isothermal titration calorimetry binding studies indicate a preference for the
disaccharide LacNAc (beta-d-galactosyl-1,4-beta-d-N-acetylglucosamine). The
molecular details of the interaction of this CBM with galactose, LacNAc, and the
type II blood group H-trisaccharide are revealed by x-ray crystallographic
studies at resolutions of 1.49, 2.4, and 2.3 A, respectively.
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Figure 4.
FIGURE 4. Representative electron density and interaction
of CpCBM32 with galactose (A), LacNAc (B), and the type II blood
group H-trisaccharide (C). All maps are maximum-likelihood/  [A]
(37)-weighted 2F[obs] - F[calc] electron density maps contoured
at 1 (0.35, 0.30, and 0.29
electrons/Å^3 for galactose, LacNAc, and the
H-trisaccharide, respectively). The disordered loop in the
galactose complex is shown with a dashed line. Amino acid side
chains involved in binding the sugars are shown in gray stick
representation and labeled.
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Figure 5.
FIGURE 5. Schematics showing the interactions of CpCBM32
with galactose (A), LacNAc (B), and the type II blood group
H-trisaccharide (C). A distance of 3.2 Å was used as the
cut-off for determination of significant hydrogen bonds. Water
molecules are shown as shaded spheres.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2006,
281,
37748-37757)
copyright 2006.
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