日本蛇根草查尔酮合酶基因的克隆及其生物信息学分析

Cloning and Bioinformatics Analysis of CHS Genes in Ophiorrhiza japonica

查尔酮合酶(CHS)是类黄酮生物合成过程中的第一个关键酶,其在类黄酮的合成过程中发挥着非常重要的作用。本研究以日本蛇根草为研究材料,根据其转录组测序结果设计全长引物,通过RT-PCR方法成功克隆得到日本蛇根草查尔酮合酶基因完整的cDNA序列,并利用相关生物信息学软件对其进行分析。结果表明,该基因序列全长为1 170 bp,编码389个氨基酸,预测其蛋白分子量为42.783 kD,等电点为6.05,是亲水性蛋白质,不含有信号肽,很可能定位在细胞质中。同时,二级结构分析显示,日本蛇根草CHS的二级结构分别由180个α螺旋、84个延伸链、125个无规则卷曲组成,这与三维结构预测结果相一致。日本蛇根草CHS基因的克隆对于研究植物类黄酮的生物合成及其分子机制具有重要意义,同时也丰富了双子叶植物PKS基因家族的相关研究。

Chalcone synthase（CHS） is the first key enzyme in the flavonoid biosynthetic pathway,and it plays an important role during flavonoid biosynthesis.In this study,we used Ophiorrhiza japonica as materials,and designed the primers according to the result of its transcriptome sequencing.The integrated cDNA of CHS was cloned successfully by RT-PCR method,and then was applied to bioinformatics analyses.These results showed that the full-length CDS of CHS was 1 170 bp,and encoded the protein which consisted of 389 amino acids.The putative protein molecular weight was 42.783 kD and its isoelectric points were 6.05.CHS of Ophiorrhiza japonica was a hydrophilic protein,had no signal peptide,and was likely to locate in the cytoplasm.Meanwhile,analysis of secondary structure indicated that CHS of Ophiorrhiza japonica contained 180 alpha helixs,84 extended strands,125 random coils,and this result was consistent with the prediction of its three dimensional structure.Cloning of CHS from Ophiorrhiza japonica has an important significance for the research of flavonoid biosynthesis and its molecular mechanism in plants,but also enriches the correlation of PKS gene family members in dicotyledones plants.