摘要
根据紫花苜蓿LEA3-1 mRNA(EU665182)的cDNA序列,设计1对特异引物,以经过ABA干旱胁迫处理的黄花苜蓿为材料,提取总RNA。采用RT-PCR方法克隆获得了747 bp的cDNA片段,命名为MfLEA3-1(GenBank登录号:HQ327439)。推测该序列编码了248个氨基酸,这些氨基酸主要由10.1%苏氨酸(Thr)、24.6%丙氨酸(Ala)、17.7%赖氨酸(Lys)和12.9%天冬氨酸(Asp)组成,不含有半胱氨酸和色氨酸,这与其他物种LEA蛋白成分非常接近。该氨基酸序列中存在13个11-mer重复序列,根据第3组蛋白分类标准,MfLEA3-1蛋白比较接近于type I,但是11-mer重复中残基分布与type I有所不同,推测MfLEA3-1蛋白属于新的第3组LEA蛋白类型。黄花苜蓿中成功获得了LEA3基因片段,为最终克隆黄花苜蓿LEA3基因序列全长奠定基础。
According to cDNA sequence of LEA3-1mRNA（Accession number：EU665182） of Medicago sativa,a pair of specific primers were designed.A new cDNA fragment of 747 bp was amplified by RT-PCR from total RNA of Medicago falcata after ABA drought stress,named MfLEA3-1 gene（GenBank accession number HQ327439）.Sequencing result supposed that it might encode 248 amino acids,which was made up of Thr（10.1%）,Ala（24.6%）,Lys（17.7%）,Asp（12.9%） except for Cys and Trp.This is similar to the LEA proteins component of other species.Otherwise,11-mer repeat sequences were involved in this amino acid sequences.According to the classification standards of type I and type II of the third set of protein,the protein of MfLEA3-1 is closed to type I,but the residue distribution of 11-mer is different to that of type I,thus,it is supposed that MfLEA3-1 protein belonged to the third set of LEA protein.The prediction results of secondary structure indicated that it was composed of α-helix.In this study,homologous sequences of LEA3 were received from Medicago falcata,which provided the foundation for cloning the full length of LEA3 of Medicago falcata.
出处
《生物技术通报》
CAS
CSCD
北大核心
2011年第7期82-87,共6页
Biotechnology Bulletin
基金
国家高技术研究发展计划("863"计划)项目(2009AA10Z108)
内蒙古自然科学基金项目(2009MS0404)
内蒙古科技重大项目(20091401)
