植物胆碱单氧化酶的生物信息学分析

Bioinformatics Analysis of Choline Monooxygenase in Plants

为了研究胆碱单氧化物酶的抗逆机理,运用NCBI、Expasy、Psort、NetPhosK、TMHMM、NPSA网站和MEGA5、DNAman软件,对已在GenBank数据库中注册中的甜菜、菠菜、四翅滨藜草、山菠菜、苋菜等植物胆碱单氧化酶的氨基酸序列进行生物信息学分析。结果表明:植物胆碱单氧化酶中Ala、Ser、Leu等氨基酸含量较丰富,属于稳定蛋白;不同植物胆碱单氧化酶的氨基酸序列具有较高的同源性(81.52%),均含有转运肽区、2Fe-S中心区和非血红素Fe离子结合区;分子进化树揭示胆碱单氧化酶有较强的保守性,可作为植物遗传分化和分子进化研究的重要依据;分子中不存在跨膜结构域,与疏水区域预测结果一致;可能受蛋白激酶C磷酸化,位点为Ser326;无规卷曲是多肽链中大量的结构元件;包含2个功能结构域,分属于Rieske家族与SRPBCC家族。本研究结果为开展胆碱单氧化酶的酶学特性及甘氨酸甜菜碱生物合成的分子机理研究提供理论参考。

In order to study the resistant mechanism of choline monooxygenase （CMO）, bioinformatics analysis of CMO from GenBank, including Beta vulgaris, Spinaeia oleracea, Atriplex prostrate, Atriplex hortensis, Amaranthus tricolor, etc. were employed by NCBI, Expasy, Psort, NetPhosK, TMHMM, NPSA web and MEGA5, DNAman software. The results were listed as follows. CMO, which had abundant Ala, Ser and Leu, belonged to a type of stable protein. The amino acid sequence of CMO in different plants showed an identity of 81.52%, containing transit peptide, Rieske type Fe-S cluster motif and non-heine Fe binding motif. Phylogenetic tree analysis indicated that CMO had highly structural conservation, and could be used for the plants genetic differentiation and molecular evolution research. There was no transmembrane domain, which was consistent with the prediction of hydrophobic domain. The protein could be phosphorylated by protein kinase C, with the potential phosphorylated site Ser326. Random coil was the major structural element of polypeptide chain. CMO contained two functional domains which belonged to Rieske-type super family and SRPBCC-type super family respectively. The result provided theoretical reference for studies on both the enzymatic characteristics of CMO and the biosynthesis pathway of glycine betaine.