Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, 90014, Oulu, Finland.
Cell Mol Life Sci. 2018 Mar;75(5):833-848. doi: 10.1007/s00018-017-2659-x. Epub 2017 Sep 20.
Glycosyltransferases (GTases) transfer sugar moieties to proteins, lipids or existing glycan or polysaccharide molecules. GTases form an important group of enzymes in the Golgi, where the synthesis and modification of glycoproteins and glycolipids take place. Golgi GTases are almost invariably type II integral membrane proteins, with the C-terminal globular catalytic domain residing in the Golgi lumen. The enzymes themselves are divided into 103 families based on their sequence homology. There is an abundance of published crystal structures of GTase catalytic domains deposited in the Protein Data Bank (PDB). All of these represent either of the two main characteristic structural folds, GT-A or GT-B, or present a variation thereof. Since GTases can function as homomeric or heteromeric complexes in vivo, we have summarized the structural features of the dimerization interfaces in crystal structures of GTases, as well as considered the biochemical data available for these enzymes. For this review, we have considered all 898 GTase crystal structures in the Protein Data Bank and highlight the dimer formation characteristics of various GTases based on 24 selected structures.
糖基转移酶（GTases）将糖基部分转移到蛋白质、脂质或现有的糖或多糖分子上。GTases 是高尔基体中重要的酶类之一，在那里发生糖蛋白和糖脂的合成和修饰。高尔基体 GTases 几乎无一例外地都是 II 型整合膜蛋白，其 C 末端球状催化结构域位于高尔基体腔中。这些酶本身根据其序列同源性分为 103 个家族。蛋白质数据库（PDB）中已经有大量发表的 GTase 催化结构域的晶体结构。所有这些结构都代表了两种主要特征结构折叠 GT-A 或 GT-B 中的一种，或者呈现出它们的变体。由于 GTases 在体内可以作为同型或异型复合物发挥作用，我们总结了晶体结构中 GTases 二聚化界面的结构特征，并考虑了这些酶的生化数据。在本次综述中，我们考虑了蛋白质数据库中的所有 898 个 GTase 晶体结构，并根据 24 个选定的结构突出了各种 GTase 的二聚体形成特征。
