摘要： 为了探索植物凝集素在分子水平的作用机理,利用RT-PCR技术从中国水仙(Narcissus tazetta var.chinensis)金盏银台中克隆到一个新的编码凝集素的基因.序列分析与预测结果表明,该基因cDNA片段总长为609 bp,含有一个由25个氨基酸残基组成的信号肽和一个519 bp的完整开放阅读框;编码172个氨基酸,分子量为18 712.31 Da;前体蛋白在氨基酸水平上与杂种多花水仙凝集素、雪花莲凝集素、石蒜凝集素的一致性分别为83%,81%和77%;其二级结构以α-螺旋、不规则盘绕和延伸链为主;三级结构与雪花莲凝集素极其相似,是一种能与D-甘露糖特异性结合的B型凝集素.

关键词: 中国水仙, 凝集素基因(NTL1), 序列分析, 性质预测

Abstract: A new lectin gene ( NTL1)was cloned from Narcissus tazetta var. chinensis′Jinzhanyintai′.The results of sequence analysis indicated that the cDNA was 609 bp in length with an open reading frame (ORF)which was capable of encoding 172 amino acids;the protein precursor composed of a signal peptide with 25 amino-acid residue and a mature protein with 148 amino-acid residues,and its molecular weight was 18 712131 Da. The homologous analysis showed that the identity between NTL1 and Narcissus hybrid cultivar lectin,Galanthus nivalis lectin and Lycoris radiata lectin was 83 %,81 % and 77 % respectively.Characteristic prediction results indicated that the secondary structure of NTL1 includedα-helix,random coil and extended strandmainly,and its three - dimensional structure strongly resembled the snowdrop lectin,therefore the NTL1 should belong to bulb - type mannose specific binding lectin

Key words: Narcissus tazetta var. chinensis, Lectin gene (NTL1) , Sequence analysis, Characteristic prediction

中图分类号: 

• S682.2+1