Abstract:
Fucose is a monosaccharide commonly found in mammalian, insect, microbial and plant glycans. The removal of terminal α-l-fucosyl residues from oligosaccharides and glycoconjugates is catalysed by α-l-fucosidases. To date, glycoside hydrolases (GHs) with exo-fucosidase activity on α-l-fucosylated substrates (EC 3.2.1.51, EC 3.2.1.-) have been reported in the GH29, GH95, GH139, GH141 and GH151 families of the Carbohydrate Active Enzymes (CAZy) database. Microbes generally encode several fucosidases in their genomes, often from more than one GH family, reflecting the high diversity of naturally occuring fucosylated structures they encounter. Functionally characterised microbial α-l-fucosidases have been shown to act on a range of substrates with α-1,2, α-1,3, α-1,4 or α-1,6 fucosylated linkages depending on the GH family and microorganism. Fucosidases show a modular organisation with catalytic domains of GH29 and GH151 displaying a (β/α)8-barrel fold while GH95 and GH141 show a (α/α)6 barrel and parallel β-helix fold, respectively. A number of crystal structures have been solved in complex with ligands, providing structural basis for their substrate specificity. Fucosidases can also be used in transglycosylation reactions to synthesise oligosaccharides. This mini review provides an overview of the enzymatic and structural properties of microbial α-l-fucosidases and some insights into their biological function and biotechnological applications.
摘要:
岩藻糖是哺乳动物中常见的单糖,昆虫,微生物和植物聚糖。α-1-岩藻糖苷酶催化从寡糖和糖缀合物中去除末端α-1-岩藻糖基残基。迄今为止,在α-1-岩藻糖基化底物上具有外岩藻糖苷酶活性的糖苷水解酶(GHs)(EC3.2.1.51,EC3.2.1。-)已在碳水化合物活性酶(CAZy)数据库的GH29,GH95,GH139,GH141和GH151家族中进行了报道。微生物通常在其基因组中编码几种岩藻糖苷酶,通常来自一个以上的GH家族,反映了他们遇到的天然岩藻糖基化结构的高度多样性。功能表征的微生物α-1-岩藻糖苷酶已显示作用于一系列具有α-1,2、α-1,3、α-1,4或α-1,6岩藻糖基化键的底物,这取决于GH家族和微生物。岩藻糖苷酶显示出模块化组织,GH29和GH151的催化结构域显示出(β/α)8桶折叠,而GH95和GH141显示出(α/α)6桶和平行的β螺旋折叠,分别。许多晶体结构已经解决了与配体的络合物,为其底物特异性提供结构基础。岩藻糖苷酶也可用于转糖基反应以合成寡糖。这篇小型综述概述了微生物α-1-岩藻糖苷酶的酶和结构特性,并对其生物学功能和生物技术应用进行了一些了解。