School of Life Sciences, Department of Biomedical Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
Adv Protein Chem Struct Biol. 2012;87:87-115. doi: 10.1016/B978-0-12-398312-1.00004-4.
The biosynthesis of the complex carbohydrates that govern many cellular functions requires the action of a diverse range of selective glycosyltransferases (GTs). Uridine diphosphate sugar-utilizing GTs (UGTs) account for the majority of characterized GTs. GTs have been classified into families (currently 92) based on amino-acid sequence similarity. However, as amino-acid sequence similarity cannot reliable predict catalytic mechanism, GTs have also been grouped into four clans based on catalytic mechanism and structural fold. GTs catalyze glycosidic bond formation with two possible stereochemical outcomes: inversion or retention of anomeric configuration. All UGTs also belong to one of two distinct structural folds, GT-A and GT-B. UGTs have conserved residues that are associated with nucleotide diphosphate sugar recognition and acceptor recognition. UGT diversification has been performed using in vitro DNA recombination, domain swapping, and random mutagenesis.
复杂碳水化合物的生物合成控制着许多细胞功能，这需要多种选择性糖基转移酶（GTs）的作用。尿苷二磷酸糖利用 GTs（UGTs）占已鉴定 GTs 的大多数。GTs 已根据氨基酸序列相似性分为家族（目前为 92 个）。然而，由于氨基酸序列相似性不能可靠地预测催化机制，GTs 也根据催化机制和结构折叠分为四个族。GTs 催化糖苷键形成，具有两种可能的立体化学结果：异头构型的反转或保留。所有 UGTs 也属于两种不同结构折叠之一，GT-A 和 GT-B。UGTs 具有与核苷酸二磷酸糖识别和受体识别相关的保守残基。UGT 的多样化是通过体外 DNA 重组、结构域交换和随机诱变来实现的。
