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 C₈₃₃ H1₃₄₈ N₂₅₄ S₄ ,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. radiate and Elaeis guineensis Jacq. is the nearest.