天人菊matK基因克隆及生物信息学分析

Clone and bioinformatics analysis of matK Gene in Gaillardia pulchella

为了完善天人菊的遗传信息,丰富菊科植物分子生物学分析数据.通过PCR扩增、基因克隆获得天人菊matK基因的完整核苷酸序列,采用生物信息学方法分析天人菊matK蛋白的结构及性质,并与其他12种matK氨基酸序列进行对比,构建系统进化树.结果表明,天人菊matK基因全长1296 bp,可编码432个氨基酸,二级结构以α-螺旋为主,无跨膜结构,无信号肽,是不稳定亲水性蛋白,存在于叶绿体中,matK氨基酸序列在不同的生物种类中具有高度的保守性.天人菊matK蛋白与遗传距离较近的菊科植物蛋白相比仅有15处氨基酸变异位点,而与遗传距离较远的加州玫瑰和北美黑莓对比存在138处氨基酸变异位点,且基因的5′端氨基酸变异频率低于3′端.基因本体论分析可知matK蛋白在13种不同的生物中可靠度为60%~70%,具有多种分子功能,并参与了众多的生物学过程.对天人菊matK基因进行了深入的分析,为天人菊的进一步研究提供了理论依据.

The study improved the genetic understanding of Gaillardia pulchella and enriched the molecular biological data of Compositae plants.Besides,the complete nucleotide sequence of matK gene by PCR amplification and gene cloningwas obtained.The bioinformatics method was used to analyze the structure and properties of matK protein,and Gaillardia pulchella with other 12 amino acid sequences of matK were compared,and N-J tree was built.According to the results,the total length of matK gene is 1296 bp,which can encode 432 amino acids.The secondary structure is mainlyα-helix,and there is no transmembrane structure and no signal peptide,which is an unstable hydrophilic protein existing in chloroplasts.The amino acid sequence of matK is highly conserved in different species.The matK protein of Gaillardia pulchella has 15 amino acid mutation sites compared with other genetically similar Chrysanthemum plant proteins.While compared with the Rose californica and Rubusursinus proteins with a longer genetic distance,the matK proteinof Gaillardia pulchella has 138 amino acid mutation sites,and the mutation frequency of 5′terminal nucleotides is lower than that of 3′terminal nucleotides.According to the genetic ontology analysis,the reliability of matK protein in 13 different organisms is 60%to 70%.The matK protein has a variety of molecular functions and participates in many biological processes.Our results provide a theoretical basis for the future study of the matK gene in Gaillardia pulchella.