水稻水溶性环氧化合物水解酶的生物信息学分析

Bioinformatics analysis on epoxide hydrolase of rice(Oryza sativa)

水溶性环氧化合物水解酶(Soluble Epoxide Hydrolase,SEH)是一组催化环氧化合物水解为相应邻位二醇的酶类,在哺乳动物、植物、昆虫和微生物体内广泛存在。通过BLAST对水稻基因组的蛋白质数据库进行搜索,获得10个水溶性环氧化物水解酶(Soluble Epoxide Hydrolase SEH)sEH蛋白的同源序列。经分析发现这些基因在水稻不同胁迫处理下各个部位都有所表达,而且不同成员之间的表达模式存在较大的差异。水稻sEH蛋白主要参与角质层形成,应激反应,以及病原防御等生理过程,特别在脱毒过程中扮演着重要的角色。对蛋白质多序列联配和三级结构预测结果表明:水溶性环氧化合物水解酶的核心结构域由3个催化残基Asp、His和Asp形成三位一体的催化活性构象。这类基因的表达受抗逆环境诱导,其功能与抗逆性有关,为基因工程抗逆育种提供了参考。

Soluble Epoxide hydmlase （sEH） comprise a group of functionally related enzymes that catalyse the addition of water to oxirane compounds （epoxides）, thereby usually generating vicinal trans- diols, sEH have been found in all types of living organisms, including mammals, invertebrates, plants, fungi and bacteria. We have used BLAST scan strategy, ten sEH like proteins were identified by searching the Oryza sativa L. ssp. japonica protein database. Expression analysis showed each gene expressed diversely within any individual, this tends suggested specific fimction of particular gene, which also showed these gene play an important role in the biosynthesis of cuticular components, strengthening and repairing the cuticle damage caused by pathogen attack. Alignment of amino acid sequences and prediction of protein three - dimensional structares suggested that the catalytic triad of plant sEH is composed of the residues Asp,His,and Asp the amino acid residues flanking the nucleophile significantly influence kinetic parameters of the enzymatic reaction.