遗传 ›› 2005, Vol. 27 ›› Issue (6): 941-947.

• 研究报告 • 上一篇    下一篇

一个小麦ω-醇溶蛋白基因同源序列的分离与序列分析

陈凡国; 夏光敏   

  1. 山东大学生命科学学院, 济南 250100
  • 收稿日期:2004-12-27 修回日期:2005-05-19 出版日期:2005-12-10 发布日期:2005-12-10
  • 通讯作者: 夏光敏

Isolation and Sequence Analysis of A ω-Gliadin Homologous Gene from Wheat

CHEN Fan-Guo, XIA Guang-Min   

  1. School of Life Science, Shandong University, Jinan 250100,China
  • Received:2004-12-27 Revised:2005-05-19 Online:2005-12-10 Published:2005-12-10
  • Contact: Guangmin Xia

摘要: 通过基因组PCR克隆了小麦济南177的一个ω-醇溶蛋白基因同源序列(ω1236),该序列包括部分5′、3′ 侧翼序列和全部可能的编码序列,没有内含子,但在第87、117、125、160、198、313、357和365氨基酸残基处有终止密码子,所有8个终止密码的形成都是碱基转换的结果。比较分析发现,该序列与一个ω-醇溶蛋白基因序列(AB059812)有98%的同源性。推导的氨基酸序列表明该基因符合禾谷类醇溶蛋白的特点。系统进化分析表明,该序列与小麦ω醇溶蛋白在进化上亲缘关系较近,与α-,β-,γ-醇溶蛋白基因关系较远。ω1236推导的氨基酸序列编码了一个可能的47.2 kDa的蛋白质。转化大肠杆菌发现,在IPTG诱导后最初2 h,有小肽段产生,这说明在该基因序列中可能存在终止密码,这与测序结果是一致的。该研究为用PCR技术克隆ω醇溶蛋白基因和进一步研究ω醇溶蛋白基因的结构和功能积累了资料。

关键词: ω醇溶蛋白基因, 小麦, 假基因, 贫硫谷蛋白, 碱基转换

Abstract: The DNA sequence of a full-length Triticum astivum CV. Jinan 177ω-gliadin homologous gene (ω1236) containing partial 5′and 3′ flanking sequences with no intron was cloned by genomic PCR-based technology. Theω1236 sequence possibly encode a putative 47.2 kDa protein except for eight stop codons at amino acid residue positions 87, 117, 125, 157, 198, 313, 357 and 365 respectively. All the eight stop codons were caused by base transition. Sequence analysis revealed thatω1236 had 98% homology to aω-gliadin gene of wheat (AB059812). Like all other gliadin gene families characterized in cereals, this gene possessed all the features in other plant reported previously. Phylogenetic analysis of the completely sequenced gene as well as those ω-genes in wheat, ω-secalin and C-horden genes in rye and barley, and α-,β- andγ-gliadin genes in wheat indicated that theω1236 was more closely related toω-gliadin gene family, much less homology toα- , β- andγ-gliadin gene families. Short peptide was produced in the culture of transformed E. coli induced by IPTG in early 2 h. It indicated that stop codon would be inω1236. The result is consistent with that of the sequenced gene. The present paper could accumulate data useful for both ω-gliadin gene cloning by PCR and the study on structures and functions of these genes.

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