Phylogenetic analysis of the UDP-glycosyltransferase multigene family of Arabidopsis thaliana
Phylogenetic analysis of the UDP-glycosyltransferase multigene family of Arabidopsis thaliana
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DOI：
10.1074/jbc.m007447200
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发表时间：
2001-02-09
影响因子：
4.8
通讯作者：
Bowles, DJ
中科院分区：
文献类型：
--
作者：
Li, Y;Baldauf, S;Bowles, DJ
一类由存在C末端共有序列所定义的尿苷二磷酸 - 糖基转移酶（UGTs）在植物界和动物界均有发现。哺乳动物的酶使用尿苷二磷酸 - 葡萄糖醛酸，而植物的酶在转移反应中通常使用尿苷二磷酸 - 葡萄糖。各种各样的糖苷配基可被这些UGTs糖基化。在植物中，糖苷配基包括植物激素、参与胁迫和防御反应的次生代谢物以及诸如除草剂之类的外源性物质。已知糖基化可调节糖苷配基的许多特性，例如它们的生物活性、溶解性以及在细胞内和整个植物中的运输特性。作为提供一个框架以开始理解植物UGTs的底物特异性和结构 - 功能关系的一种手段，我们现在对拟南芥中99个UGT序列的多基因家族进行了分子系统发育分析。我们以令人惊讶的高置信度确定了各个成员之间的整体组织和进化关系。通过构建一个综合的系统发育树，其中还包括所有具有已知催化活性的其他植物UGTs，我们可以开始预测新序列在被鉴定时的进化历史和底物特异性。该树已经表明，虽然UGT家族的一些亚组的活性在不同植物物种中高度保守，但其他亚组相对容易改变底物特异性。
A class of UDP-glycosyltransferases (UGTs) defined by the presence of a C-terminal consensus sequence is found throughout the plant and animal kingdoms. Whereas mammalian enzymes use UDP-glucuronic acid, the plant enzymes typically use UDP-glucose in the transfer reactions. A diverse array of aglycones can be glucosylated by these UGTs. In plants, the aglycones include plant hormones, secondary metabolites involved in stress and defense responses, and xenobiotics such as herbicides. Glycosylation is known to regulate many properties of the aglycones such as their bioactivity, their solubility, and their transport properties within the cell and throughout the plant. As a means of providing a framework to start to understand the substrate specificities and structure-function relationships of plant UGTs, we have now applied a molecular phylogenetic analysis to the multigene family of 99 UGT sequences in Arabidopsis. We have determined the overall organization and evolutionary relationships among individual members with a surprisingly high degree of confidence. Through constructing a composite phylogenetic tree that also includes all of the additional plant UGTs with known catalytic activities, we can start to predict both the evolutionary history and substrate specificities of new sequences as they are identified. The tree already suggests that while the activities of some subgroups of the UGT family are highly conserved among different plant species, others subgroups shift substrate specificity with relative ease.