苏云金芽孢杆菌以色列亚种P19基因的初步研究

PRELIMINARY STUDY OF P19 GENE FROM BACILLUS THURINGIENSIS SUBSP ISRAELENSIS

以含有Ｐ１９和ｃｙｔ１Ａ基因的以色列亚种７２ＭＤ质粒的９７ｋｂＨｉｎｄⅢ片段为模板进行ＰＣＲ扩增，分别获得Ｐ１９基因和ｃｙｔ１Ａ基因片段。与表达载体ｐＵＨＥ２４连接转化大肠杆菌ＸＬ１，获得３个克隆株。ＬＺ１９含有Ｐ１９基因；ｐＬＺｃｙｔ１Ａ含有ｃｙｔ１Ａ基因；ＬＺ１９Ａ含有Ｐ１９和ｃｙｔ１Ａ两个基因。利用ｃｙｔ１Ａ蛋白质可使大肠杆菌细胞致死的特性，在ＩＰＴＧ诱导下，测定了各克隆基因表达对大肠杆菌有致死作用；ｐＬＺ１９Ａ对大肠杆菌的起始致死作用明显快于ｐＬＺｃｙｔ１Ａ，这种现象可能是Ｐ１９基因促进ｃｙｔ１Ａ基因高表达的结果。

The P19 gene and cyt1 A gene were obtained by PCR with 9 7kb HindIII fragment containing P19 gene and cyt 1A gene from 72MD plasmid of Bt as a template.Digested PCR producs were ligated to expression vector pUHE24 and transformed into E.coli XL 1.Three clones,LZ19 harboring P19 gene,LZcyt1A harboring cyt 1A gene,LZ19A harboring P19 gene and cyt1 A gene,were screened.The growth cure of cloned strains were determined under IPTG indution.The result showed that pLZ19 did not affect the growth of E.coli ,pLZcyt1A is typically Lethal for E.coli, Lethal initial effeciency of pLZ19A is much higher than that of pLZcyt1A.Probably,this was a result that P19 gene enhanced initial expression of cyt1 A gene in E.coli .