Abstract：
Glycosyltransferases (GTs) are carbohydrate-active enzymes that are encoded by the genomes of organisms spanning all domains of life. GTs catalyze glycosidic bond formation, transferring a sugar monomer from an activated donor to an acceptor substrate, often another saccharide. GTs from family 47 (GT47, PF03016) are involved in the synthesis of complex glycoproteins in mammals and insects and play a major role in the synthesis of almost every class of polysaccharide in plants, with the exception of cellulose, callose, and mixed linkage β-1,3/1,4-glucan. GT47 enzymes adopt a GT-B fold and catalyze the formation of glycosidic bonds through an inverting mechanism. Unlike animal genomes, which encode few GT47 enzymes, plant genomes contain 30 or more diverse GT47 coding sequences. Our current knowledge of the GT47 family across plant species brings us an interesting view, showcasing how members exhibit a great diversity in both donor and acceptor substrate specificity, even for members that are classified in the same phylogenetic clade. Thus, we discuss how plant GT47 family members represent a great case to study the relationship between substrate specificity, protein structure, and protein evolution. Most of the plant GT47 enzymes that are identified to date are involved in biosynthesis of plant cell wall polysaccharides, including xyloglucan, xylan, mannan, and pectins. This indicates unique and crucial roles of plant GT47 enzymes in cell wall formation. The aim of this review is to summarize findings about GT47 enzymes and highlight new challenges and approaches on the horizon to study this family.
摘要：
糖基转移酶（GT）是碳水化合物活性酶，由跨越生命所有域的生物体基因组编码。GTs催化糖苷键形成，将糖单体从激活的供体转移到受体底物，通常是另一种糖。来自家族47的GTs（GT47，PF03016）参与哺乳动物和昆虫中复杂糖蛋白的合成，并在植物中几乎所有类别的多糖的合成中起主要作用。除了纤维素,Callose,和混合连接的β-1,3/1,4-葡聚糖。GT47酶采用GT-B折叠并通过反转机制催化糖苷键的形成。与动物基因组不同,编码很少的GT47酶，植物基因组包含30种或更多种GT47编码序列。我们目前对植物物种GT47家族的了解给我们带来了一个有趣的观点，展示成员如何在供体和受体底物特异性方面表现出极大的多样性，即使是属于同一系统发育进化枝的成员。因此，我们讨论了植物GT47家族成员是如何代表研究底物特异性之间关系的一个很好的案例，蛋白质结构，和蛋白质进化。迄今为止鉴定的大多数植物GT47酶都参与植物细胞壁多糖的生物合成，包括木葡聚糖,木聚糖,甘露聚糖,还有果胶.这表明植物GT47酶在细胞壁形成中的独特和关键作用。这篇综述的目的是总结有关GT47酶的发现，并强调研究该家族的新挑战和新方法。
