毛竹中黄酮-C-糖基转移酶基因的克隆和生物信息学分析

Cloning and Bioinformatics Analysis of Flavonoid-C-glycosyl-transferase Gene from Phyllostachys edulis

糖基转移酶是催化黄酮糖苷形成的关键酶。黄酮糖苷类化合物具有抗氧化、清除自由基、调节血脂和血糖等生理作用。基于毛竹基因库测序的完成,本研究通过RT-PCR技术首次获得一条完整的毛竹黄酮-C-糖基转移酶基因开放阅读框,将其命名为PeCGT,其基因的序列长度是1342 bp。对其编码蛋白的理化性质、保守结构域以及二级结构和空间结构等进行了生物信息学分析。结果表明:PeCGT基因编码的蛋白含有447个氨基酸,分子量是47.76 kD,理论等电点为4.91,酸性氨基酸(Asp+Glu)个数为54,碱性氨基酸(Arg+Lys)个数为35。PeCGT蛋白是疏水型蛋白,不存在信号肽,存在于线粒体中。结构域预测分析结果表明,PeCGT编码的氨基酸序列具有明显的糖基转移酶特征的保守域结构PSPG。通过同源性分析,其与乌拉图小麦(Triticum urartu)、节节麦(Aegilops tauschii subsp.Tauschii)和二穗短柄草(Brachypodium distachyonhiihii)具有较高的同源性。实时荧光定量PCR结果表明:PeCGT基因在叶中的表达量最高,在根中几乎不表达,在茎中有部分表达。此研究结果为以后毛竹黄酮-C-糖基转移酶的表达和功能鉴定提供了一定的帮助。

Glycosyltransferase is the main enzyme that catalyze the formation of flavonoid glycosides.Flavonoid glycosides have physiological effects such as anti-oxidation,scavenging free radicals,regulating blood lipids and blood sugar.In this study,a complete open reading frame of the flavonoid-C-glycosyltransferase gene was obtained by RT-PCR and named as Pe CGT.It was based on the completion of the sequencing of the Phyllostachys edulis gene library.The gene has a sequence length of 1342 bp.Bioinformatics analysis of PeCGT was carried out,including physical and chemical properties,conservative domain,secondary structure and spatial structure.The results showed that the protein encoded by this gene contains 447 amino acids,its molecular weight is 47.76 kD,the theoretical isoelectric point is 4.91.And the number of acidic amino acids(Asp+Glu)is 54,the number of basic amino acids(Arg+Lys)is 35.The protein is a hydrophobic protein with no signal peptide present,which is present in the mitochondria.By domain prediction analysis,the PeCGT contains a distinct glycosyltransferase conserved domain structure.Through homology analysis,it has high homology with Triticum urartu,Aegilops tauschii subsp.Tauschii and Brachypodium distachyonhii.It was found by Q-PCR that PeCGT expressed the least amount in roots,the highest expression in leaves,and was partially expressed in stems.This study could be helpful for the expression and functional identification of flavonoid-C-glycosyltransferase in Phyllostachys edulis.