钩刺山羊草(Aegilops triuncialis)低分子量谷蛋白基因序列分析

根据低分子量谷蛋白亚基(LMW-GS)基因编码区保守序列设计引物,对钩刺山羊草(AegilopstriuncialisL,2n=4x=28,CCUU)PI483029总DNA进行PCR扩增,得到长度为900和1065bp的DNA片段,克隆测序后获得2个LMW-GS基因,GenBank登录号分别为AY841016和AY841017。它们具有小麦LMW-GS基因的典型结构特征。其中,AY841017具有完整编码区,长度为1065bp,可编码322个氨基酸残基的成熟蛋白,第一个半胱氨酸残基出现在重复区第13位。在重复区,AY841017的两个疏水单元为PIIIL和PVIIL,重复区中还存在一个连续13个Q(谷氨酰胺)组成的短肽。AY841016由于编码区内存在提前终止密码子,为假基因。氨基酸序列比较发现,AY841017与普通小麦(IriticumaestivumL.)Glu-D3位点编码的LMW-GS基因有很高的一致性。

Sequence Analysis of LMW-GS Genes from Aegilops triuncialis

According to the conservative sequences of known low-molecular-weight glutenin subunit (LMW-GS) genes, the PCR primers were designed, and the full coding regions of LMW-GS genes were amplified from the genomic DNA of Aegilops triuncialis L. Two novel genes with the typical structure of LMW-GS genes, GenBank accession AY841016 and AY841017, were identified from the expected 900 and 1 065 bp amplification products, respectively. The coding region of AY841017 was 1 065 bp, and encoded a mature protein with 322 amino acid residues. The first cysteine residue of AY841017 was observed at position 13 in the repetitive domains. In the repetitive domain, the two hydrophobic motifs of AY841017 were PIIIL and PVIIL. A repeat motif with 13 glutamines (Q) was found in the repetitive domain of AY841017. Due to two stop codons in its coding region, AY841016 was a pseudogene. It was found that AY841017 was highly similar to those encoded by Glu-D3 locus.