Comprehensive analysis of glycosyltransferases in eukaryotic genomes for structural and functional characterization of glycans
Comprehensive analysis of glycosyltransferases in eukaryotic genomes for structural and functional characterization of glycans
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DOI：
10.1016/j.carres.2009.03.001
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发表时间：
2009-05-12
影响因子：
3.1
通讯作者：
Kanehisa, Minoru
中科院分区：
文献类型：
--
作者：
Hashimoto, Kosuke;Tokimatsu, Toshiaki;Kanehisa, Minoru
糖基转移酶包括高度分化的酶群，它们在复杂聚糖的合成中起着核心作用。由于基因组中的糖基转移酶决定了可合成聚糖的范围，并且由于基因组序列数据的增加，现在有必要在生物体中检查这些酶，以探索糖缀合物的可能结构和功能。在本研究中，我们系统地研究了36个真核生物基因组，获得了3426个用于主要聚糖生物合成的糖基转移酶同源物，根据序列相似性将其分为53个家族。根据生物合成途径将这些科进一步划分为6个功能类别，揭示了生物类群在保护程度和类群数量上的特征模式。结果还揭示了每个基因组中糖基转移酶的数量与编码基因的数量之间存在很强的相关性。然后，我们预测了通过糖基转移酶家族的组合在每种生物中合成主要聚糖结构的能力，包括n -聚糖前体和gpi锚点。这表明，不仅寄生原生生物，而且一些藻类也可能合成比已知的在广泛的真核生物中保守的结构更小的结构。最后，我们讨论了两个大家族，唾液基转移酶和m -糖基转移酶的功能，并进行了更精细的亚家族分类。我们的研究结果表明，糖基转移酶的普遍性和多样性源于两种类型的糖基转移酶家族的进化，即具有很少的近亲的保守家族和具有许多近亲的分化家族。2009爱思唯尔有限公司版权所有。
Glycosyltransferases comprise highly divergent groups of enzymes, which play a central role in the synthesis of complex glycans. Because the repertoire of glycosyltransferases in the genome determines the range of synthesizable glycans, and because the increasing amount of genome sequence data is now available, it is essential to examine these enzymes across organisms to explore possible structures and functions of the glycoconjugates. In this study, we systematically investigated 36 eukaryotic genomes and obtained 3426 glycosyltransferase homologs for biosynthesis of major glycans, classified into 53 families based on sequence similarity. The families were further grouped into six functional categories based on the biosynthetic pathways, which revealed characteristic patterns among organism groups in the degree of conservation and in the number of paralogs. The results also revealed a strong correlation between the number of glycosyltransferases and the number of coding genes in each genome. We then predicted the ability to synthesize major glycan structures including N-glycan precursors and GPI-anchors in each organism from the combination of the glycosyltransferase families. This indicates that not only parasitic protists but also some algae are likely to synthesize smaller structures than the structures known to be conserved among a wide range of eukaryotes. Finally we discuss the functions of two large families, sialyltransferases and M-glycosyltransferases, by performing finer classifications into subfamilies. Our findings suggest that universality and diversity of glycans originate from two types of evolution of glycosyltransferase families, namely conserved families with few paralogs and diverged families with many paralogs. (C) 2009 Elsevier Ltd. All rights reserved.