Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.
Glycobiology. 2014 Feb;24(2):108-24. doi: 10.1093/glycob/cwt101. Epub 2013 Nov 18.
Membrane-associated GT-B glycosyltransferases (GTs) comprise a large family of enzymes that catalyze the transfer of a sugar moiety from nucleotide-sugar donors to a wide range of membrane-associated acceptor substrates, mostly in the form of lipids and proteins. As a consequence, they generate a significant and diverse amount of glycoconjugates in biological membranes, which are particularly important in cell-cell, cell-matrix and host-pathogen recognition events. Membrane-associated GT-B enzymes display two "Rossmann-fold" domains separated by a deep cleft that includes the catalytic center. They associate permanently or temporarily to the phospholipid bilayer by a combination of hydrophobic and electrostatic interactions. They have the remarkable property to access both hydrophobic and hydrophilic substrates that reside within chemically distinct environments catalyzing their enzymatic transformations in an efficient manner. Here, we discuss the considerable progress that has been made in recent years in understanding the molecular mechanism that governs substrate and membrane recognition, and the impact of the conformational transitions undergone by these GTs during the catalytic cycle.
膜结合 GT-B 糖基转移酶（GTs）是一大类酶，能够催化糖基从核苷酸糖供体转移到广泛的膜结合受体底物上，主要以脂质和蛋白质的形式存在。因此，它们在生物膜中产生大量多样的糖缀合物，这些糖缀合物在细胞-细胞、细胞-基质和宿主-病原体识别事件中尤为重要。膜结合 GT-B 酶具有两个“罗斯曼折叠”结构域，由一个包含催化中心的深裂沟隔开。它们通过疏水相互作用和静电相互作用与磷脂双层永久性或暂时性结合。它们具有一个显著的特性，即能够接近位于化学上不同环境中的亲水性和疏水性底物，并以有效的方式催化它们的酶促转化。在这里，我们讨论了近年来在理解调控底物和膜识别的分子机制方面取得的重大进展，以及这些 GT 在催化循环中经历的构象转变的影响。
