Isolation of one strong gene promoter from Bacillus subtilis through shot-gun method and the expression of cattle GHRL gene.

Through shot-gun method,one hundred and three DNA segments of promoter from genomic library of 168 Bacillus subtilis were detected with Escherichia coli-B.subtilis shuttle plasmid.The activities of the reporter gene of bgaB driven by one promoter fragment,P3.4.23,exhibited high expression strength both in E.coli and B.subtilis.The fragment was 672 bp long and stronger than P43 promoter.The activities of bgaB promoted by the fragment reached to 3 418 and 2 877 U/mL in E.coli and B.subtilis,respectively.The blasting result showed that the fragment had the conserved sequences of B.subtilis promoters.The putative promoter was sub-cloned and identified,which showed that its important region for transcription,5-333 bp,is the regulatory region of yxiE gene.GHRL gene of cattle was drove by the sub-cloned promoter.The SDS-PAGE showed that GHRL gene was expressed in B.subtilis.