芜菁花叶病毒外壳蛋白基因的克隆与序列分析

Cloning and Sequence Analysis of Turnip Mosaic Virus Coat Protein Gene

根据芜菁花叶病毒（TurnipMosaicVirus，TuMV）外壳蛋白（CP）基因序列人工合成引物，用RT法合成cDNA后，通过PCR法扩增并克隆TuMV海南分离物外壳蛋白基因。结果表明，外壳蛋白基因全长864个碱基，编码288个氨基酸。与Trembly，M．F等报道的核苷酸同源率为95．8％，氨基酸同源率为94．8％。与徐平报道的核苷酸同源率为96．3％，氨基酸同源率为95．1％。与孔令洁报道的核苷酸同源率为88％，氨基酸同源率为90．6％。将CP基因插入pET－21b多克隆位点，转入E．colt后诱导表达，聚丙烯酸胺凝胶电泳分析呈现一特异的蛋白带，Westernblot检测证明，该特异带与TuMV抗血清呈阳性反应。

The cDNA of turnip mosaic virus CP gene was synthesized by RTPCR and sequenced. The TuMV CP gene consists of 864 nt encoding 288 amino acids. It was compared with three-reported TuMV CP gene's sequence. The homology of nucleotide sequences between them were 96.3 %, 95.8 % and 88 % respectively.The homology of amino acid sequences were 95. 1 %, 94.8 % and 90.6 % respectively. The CP gene was cloned into the prokaryotic expression vector pET-21b. E.coli BL21 containing the recom binant ETU-B1 was induced by IPTG. It was proved that SDS-PAGE and western blot expressed the CP gene in E. coli.