The interaction of a carbohydrate-binding module from a Clostridium perfringens N-acetyl-β-hexosaminidase with its carbohydrate receptor
The interaction of a carbohydrate-binding module from a Clostridium perfringens N-acetyl-β-hexosaminidase with its carbohydrate receptor
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DOI：
10.1074/jbc.m606126200
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发表时间：
2006-12-08
影响因子：
4.8
通讯作者：
Boraston, Alisdair B.
中科院分区：
文献类型：
--
作者：
Ficko-Blean, Elizabeth;Boraston, Alisdair B.
产气荚膜梭菌是人类胃肠道的一种显著的定殖物。从其基因组中发现的糖苷水解酶的数量来看，这种细菌对人类病原体来说是相当了不起的。这些酶的模块化是惊人的，因为经常出现氨基酸序列与家族32碳水化合物结合模块(CBM)相同的模块，通常被称为F5/8结构域。在此，我们报道了产气荚膜梭菌N-乙酰-β-氨基己糖苷酶的32个CBM家族的性质。大分子阵列、UV差值和等温滴定量热法结合研究表明，二糖更倾向于LacNAc(beta-D-galactosyl-1，4-beta-D-N-acetylglucosamine).在1.49、2.4和2.3埃的分辨率下，X射线结晶学研究揭示了该CBM与半乳糖、LacNAc和II型血型H-三糖相互作用的分子细节。
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 angstrom, respectively.