Organisation and structural evolution of the rice glutathione S-transferase gene family
Organisation and structural evolution of the rice glutathione S-transferase gene family
复制标题
DOI：
10.1007/s00438-004-1006-8
复制
发表时间：
2004-06-01
影响因子：
3.1
通讯作者：
Frova, C
中科院分区：
文献类型：
--
作者：
Soranzo, N;Gorla, MS;Frova, C
谷胱甘肽S - 转移酶（GSTs）是一个庞大的关键防御酶家族，可抵御外源性物质的毒性。在此，我们描述了这个重要的多基因家族在单子叶模式植物水稻[Oryza sativa (L.)]中的全面特征。此外，我们基于以下两方面的分析来研究该家族的分子进化：（1）基因组内重复的模式，以及（2）水稻、拟南芥、玉米和大豆的谷胱甘肽S - 转移酶之间的系统发育关系和进化分歧。通过对Genbank/EMBL/DDBJ数据库的EST和基因组部分进行计算机筛选，我们分离出了59个假定基因和2个假基因，这使其成为迄今为止所鉴定的最大的植物谷胱甘肽S - 转移酶家族。其中，38个（62%）有基因组和EST序列，23个（38%）仅从其基因组序列得知。对EST集合的初步调查显示，在不同组织和环境条件下基因表达存在很大程度的差异，少数基因（13个）占所有EST的80%。水稻谷胱甘肽S - 转移酶分为四个主要的系统发育类别，所有水稻基因中有91%属于两个植物特异性类别Tau（40个基因）和Phi（16个基因）。同一类别蛋白质的成对一致性得分在17% - 98%之间，不同类别之间的比较为7% - 21%。在1号和10号染色体上分别发现两个由7个和23个紧密相关基因组成的大簇，这表明基因重复导致了快速进化。对两个单子叶植物和两个双子叶植物物种中完整的谷胱甘肽S - 转移酶家族进行比较，结果表明所有Theta和Zeta谷胱甘肽S - 转移酶具有单系起源，并且所有Phi和Tau基因的共同祖先不超过三个。
Glutathione S-transferases (GSTs) comprise a large family of key defence enzymes against xenobiotic toxicity. Here we describe the comprehensive characterisation of this important multigene family in the model monocot species rice [Oryza sativa (L.)]. Furthermore, we investigate the molecular evolution of the family based on the analysis of (1) the patterns of within-genome duplication, and (2) the phylogenetic relationships and evolutionary divergence among rice, Arabidopsis, maize and soybean GSTs. By in-silico screening of the EST and genome divisions of the Genbank/EMBL/DDBJ database we have isolated 59 putative genes and two pseudogenes, making this the largest plant GST family characterised to date. Of these, 38 (62%) are represented by genomic and EST sequences and 23 (38%) are known only from their genomic sequences. A preliminary survey of EST collections shows a large degree of variability in gene expression between different tissues and environmental conditions, with a small number of genes (13) accounting for 80% of all ESTs. Rice GSTs are organised in four main phylogenctic classes, with 91% of all rice genes belonging to the two plant-specific classes Tau (40 genes) and Phi (16 genes). Pairwise identity scores range between 17 and 98% for proteins of the same class, and 7 and 21% for interclass comparisons. Rapid evolution by gene duplication is suggested by the discovery of two large clusters of 7 and 23 closely related genes on chromosomes I and 10, respectively. A comparison of the complete GST families in two monocot and two dicot species suggests a monophyletic origin for all Theta and Zeta GSTs, and no more than three common ancestors for all Phi and Tau genes.