The interaction of a carbohydrate-binding module from a Clostridium perfringens N-acetyl-beta-hexosaminidase with its carbohydrate receptor.
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.
Ficko-Blean
Elizabeth
E
Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
Boraston
Alisdair B
AB
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003016:Clostridium perfringens / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000235:genetics; D004187:Disaccharides / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D001619:beta-N-Acetylhexosaminidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D004269:DNA, Bacterial; D004187:Disaccharides; D001619:beta-N-Acetylhexosaminidases