千里光S-腺苷甲硫氨酸合成酶(SAMS)的结构域与功能位点分析（英文）  

Functional Role Determined by Structural Domains of S-adenosylmethionine Synthase(SAMS) in Senecio scandens Buch.-Ham.ex D.Don

作　　者：谭昊[1] 文春菊 钱倩[2] 钱刚[3] 

机构地区：[1]遵义医学院美容系,中国贵州遵义563003 [2]遵义医学院临床医学系,中国贵州遵义563003 [3]遵义医学院细胞生物学与遗传学教研室,中国贵州遵义563003

出　　处：《生命科学研究》2015年第3期203-209,共7页Life Science Research

基　　金：遵义医学院大学生创新项目([2013]6501);贵州省大学生创新项目(201410661001);贵州省优秀科技教育人才省长基金项目(黔省专合字2008-61号)~~

摘　　要：基于前期研究工作中构建的千里光全长c DNA文库,我们分离到千里光S-腺苷甲硫氨酸合成酶(Sadenosylmethionine synthase,SAMS)基因,本研究分析了该基因开放阅读框,并对该多肽3个高度保守序列形成的结构域和功能位点之间的关系进行了探讨。结果表明,该基因(Gen Bank ID:KC149908.1)编码的蛋白质由394个氨基酸残基组成,理论等电点5.48,相对分子质量43.40 k D;结构域比对和3-D模型分析结果表明,α-helix/β-strand是该蛋白结构域的主要组分,且SPOUT结构与甲基转移酶反应密切相关,其功能可能涉及核酸、蛋白质和磷脂的合成,本研究揭示SAMS的氨基酸保守基序是形成高级结构并决定其生物学功能之关键所在。Three highly conserved motifs of S-adenosylmethionine synthase（SAMS） were selected to observe the relationship between structural domains and their functional sites,based on our previous construction on a high-quality of full-length-enriched cDNA library in Senecio scandens Buch.-Ham. ex D. Don.Here, S-adenosylmethionine synthase gene（SAMS） was isolated depending on analysis of its open reading frame（ORF）. As shown in our results, cDNA clone（Gen Bank ID： KC149908.1） encodes a protein composed of 394 amino acid residues with the theoretical isoelectric point of 5.48 and the predicted molecular weight of 43.40 k D. And then, 3-D model shape alignments indicate that a genuine hydrophobic core composed of SPOUT-domain and a relaxed α-helix/β-strand complexity is a key methyl group donor for the methyltransferase reactions involving DNA, RNA, proteins, and phospholipids. This work hereby elucidates that SAMS protein binding sites are attributed to the structural properties determined by the highly conserved motifs.

关 键 词：结构域 三维模型比对 S-腺苷甲硫氨酸合成酶(SAMS) 千里光 

分 类 号：Q949.783.5[生物学—植物学]