落地生根S-腺苷高半胱氨酸水解酶基因的克隆及生物信息学分析

Cloning and Bioinformatics Analysis of S-adenosylhomocysteine Hydrolase Gene form Kalanchoe daigremontiana

为了解落地生根（Kalanchoe daigremontiana）的SAHH基因功能，采用RACE技术从其叶片克隆了SAHH的全长cDNA序列，命名为KdSAHH。结果表明，KdSAHH全长为1748 bp，含1458 bp完整的开放阅读框（ORF），推测编码485个氨基酸。预测落地生根SAHH蛋白分子量约为53 kDa，理论等电点为5.59~5.682。Scanprostie和DNAstar预测表明，落地生根SAHH蛋白在进化上非常保守，与苜蓿的亲缘关系较近。以黄羽扇豆为模板，利用SWISS-MODLE和Phyre程序模拟的落地生根SAHH蛋白亚基三维结构有一定差异。这些为落地生根KdSAHH的表达和功能研究奠定了基础。

In order to understand the function ofSAHHinKalanchoe daigremontiana, a cDNA sequence, named asKdSAHH, was cloned by RT-PCR and RACE-PCR. The results showed that the full-length ofKdSAHHcDNA was 1748 bp, encoding 485 amino acids. The predicted molecular weight （MW） of KdSAHH was about 53 kDa with estimated pI of 5.59–5.682. The Scanprostie and DNAstar prediction showed that KdSAHH protein with two conserved motifs was very conservative in evolution. There were high homology between KdSAHH and SAHHs in other species by amino acid alignment, and which had the closest relationship with that inMedicago sativa. Lupinus luteusused as template, there were differences in three-dimensional structure of KdSAHH simulated by SWISS-MODLE and Phyre. These would lay out basis for research in expression and function of KdSAHH.