石蒜核糖体蛋白L21的基因克隆及氨基酸序列分析

Gene cloning and amino acid sequence analysis of ribosomal protein L21 from Lycoris radiata

根据已知核糖体蛋白L21(RPL21)基因的保守序列设计1对引物,采用PCR技术从石蒜〔Lycoris radiata(L'Hér.)Herb.〕叶片全长cDNA文库中筛选出阳性克隆。通过测序和分析,获得1条石蒜RPL21基因全长cDNA序列,命名为LrRPL21,GenBank登录号为FJ972626;序列全长709 bp,编码1条具有164个氨基酸残基的多肽。采用多种分析程序对石蒜RPL21的理化性质以及氨基酸序列的同源性进行了分析比较。结果显示:石蒜RPL21的预测分子量为18 628,理论等电点为10.36,分子式为C833H1348N254S4,总平均疏水性指数为-0.668,为亲水性蛋白;石蒜RPL21与其他8种植物RPL21的氨基酸序列同源性百分率均较高,达到85%～95%;根据系统树可推测其与油棕(Elaeis guineensis Jacq.)RPL21的进化关系最近。

A pair of primers were designed according to the known conserved sequence of ribosomal protein L21（RPL21） gene,and the positive clone was selected from full length cDNA library of Lycoris radiata（L′Hér.） Herb.leaf by PCR technology.By means of sequencing and analyzing,a full length cDNA sequence of L.radiata RPL21 gene was obtained,which was named LrRPL21 and its GenBank accession number was FJ972626.The full length of LrRPL21 is 709 bp,which encodes a polypeptide being composed of 164 amino acid residues.Physicochemical property and amino acid sequence homology of L.radiata RPL21 were analyzed and compared by some analysis programs.The results show that the putative molecular weight and theoretical isoelectric point of L.radiata RPL21 are 18 628 and 10.36,respectively,the molecular formula is C833H1348N254S4,and the grand average index of hydrophobicity is-0.668,which is a hydrophilic protein.Homologous percentage of amino acid sequence of RPL21 between L.radiata and other eight species is higher with a percentage of 85%-95%.And according to phylogenetic tree,it can be conjectured that the evolutionary relationship of RPL21 between L.radiata and Elaeis guineensis Jacq.is the nearest.