摘要
采用cDNA末端快速扩增(RACE)技术首次获得碱蓬(Suaeda glauca)中含PEPCase基因完整编码区的cDNA序列,长度为3 038 bp。获得的序列采用生物信息学方法和系统进化方法进行分析。结果表明,获得的cDNA序列包含2 898 bp的完整开放阅读框,编码的966个氨基酸序列含有两个PEPCase活性位点以及6种其他的活性位点;预测蛋白质的相对分子质量为109 785.3,等电点为5.51,属于不稳定的亲水性蛋白;含量相对较多的氨基酸是Leu、Glu、Arg、Asp、Ser,不含Pyl和Sec;不包含跨膜结构和信号肽序列,推断为非分泌性蛋白;二级结构以α螺旋为主,三级结构为紧密球状结构;分析结果还表明获得的碱蓬PEPCase基因应该属于C3型。通过对碱蓬PEPCase基因的克隆及序列分析从而为后期碱蓬PEPCase蛋白表达的研究及获得高油量的转基因碱蓬植株奠定了基础。
PEPCase is one of key enzymes which control the ratio of protein to lipid. The cDNA sequence containing complete coding sequence of PEPCase gene was firstly obtained from Suaeda glauca by using RACE approach and this sequence was 3 038 bp. Bioinformatics methods and phylogenetic analysis method were applied to analyze the obtained sequence. The analysis results showed that this sequence contained a complete 2 898 bp ORF; the 966 encoded amino acids contained two PEPCase active sites and other six active sites; Mr was to 109 785.3, PI was to 5.51, the protein was instable and hydrophilic; the percentages of Leu, Glu, Arg, Asp and Ser were comparatively high, but there were no Pyl and Sec; there were no transmembrane helices and signal peptide and it was predicted as a non secretory protein; the secondary structure was mainly composed of a-helix, the tertiary structure appeared as a compact globular protein. phylogenetic analysis showed that the obtained PEPCase gene should belong to C3 form. Clone and sequence analysis of PEPCase gene were important to study further PEPCase protein expression and study of the transgenic S. glauca with high oil productivity.
出处
《海洋科学》
CAS
CSCD
北大核心
2009年第6期67-72,共6页
Marine Sciences
