摘要
matK基因编码唯一一种与陆地植物叶绿体Ⅱ类内含子剪接相关的成熟酶,是进化速度最快的基因之一。然而,濒危绶草matK基因的序列变异及其对蛋白分子作用力和功能的影响尚未被研究过。我们研究了9种绶草matK基因的核酸变异模式,分析了该基因在构建绶草系统进化树中的应用价值,并探讨了matK蛋白保守区域内氨基酸变异对残基分子作用力和蛋白功能的影响。研究发现9种绶草matK基因之间共存在59处碱基变异且基因5’端核苷酸变异频率高于3’端,变异碱基除位于三联密码子第3位碱基外,还大量分布于三联密码子的第1位和第2位碱基。氨基酸序列比对结果显示9种绶草matK蛋白均具有保守的domain X功能区域,该区域存在3处差异氨基酸,但氨基酸变异未引起相应氨基酸残基的分子作用力变化。基因本体论研究结果发现9种绶草matK蛋白的功能主要是结合活性,参与代谢过程、基因表达和RNA加工等生物过程反应。研究结果表明,不同绶草matK基因存在丰富的基因变异信息、其5’端序列是解决系统发育最有用的区域。不同绶草matK蛋白在进化过程中可能受到严格约束,从而导致蛋白功能高度保守。本研究确立了绶草matK基因5’端序列在系统发育分析中的应用价值,同时丰富了叶绿体matK基因的分子信息。
matK gene encodes the only maturase associated with the splicing of chloroplast group Ⅱ introns in land plants, which is one of the fastest evolutionary genes. However, the sequence variations in matK gene of endangered Spiranthes plants and the effect on the protein molecular interaction and function have not been studied. In this paper, the nucleic acid variation patterns of 9 matK genes in Spiranthes plants were studied, the application value of this gene in constructing the phylogenetic tree of Spiranthes plants was analyzed, the effects of amino acid variation in the conserved region of matk proteins on the residue interaction and protein function were also discussed. The results showed that there were 59 nucleotide variants in 9 matK genes, and the mutation frequency of 5’ terminal nucleotides was higher than that of 3’ terminal nucleotides. The variation bases were located at the 3 rdpositions of the triple codons, and they were also widely distributed at the 1 stand 2 ndpositions of the triple codons. The amino acid sequence alignment results showed that all 9 matK proteins had a conserved domain X function region, in which there were 3 different amino acids, but the change of amino acids did not cause the change of molecular interaction of the corresponding amino acid residue. The gene ontology results showed that the functions of 9 matK proteins of Spiranthes plants were mainly binding activity and involved in the biological reactions of metabolic process, gene expression and RNA processing. The results indicate that there is abundant information of genetic variation in different matK genes, the 5-end sequence is the most useful area for phylogenetic analysis, and different matK proteins may be severely restricted in the course of evolution, which leads to the high conservatism of protein function. This study established the value of 5’-terminal sequence of matK gene in phylogenetic analysis of Spiranthes plants, and enriched the molecular information of chloroplast matK gene.
作者
陈慧
黄晓英
黄明远
张西玉
范晶
Chen Hui;Huang Xiaoying;Huang Mingyuan;Zhang Xiyu;Fan Jing(College of Life Science,Leshan Normal University,Leshan,614004)
出处
《分子植物育种》
CAS
CSCD
北大核心
2019年第21期7017-7030,共14页
Molecular Plant Breeding
基金
四川省教育厅科研项目(16ZA0302
15ZB0257)
国家级大学生创新创业训练计划项目(201510649017)共同资助
