Bent promoter of epsilon-toxin gene from Clostridium perfringens : analysis and application to protein expressions.

点击翻译按钮获取中文摘要

Phased A-tracts form a bent structure of DNA. We found a novel type of bent DNA structure, which stimulates the gene transcription, downstream of a Clostridium perfringens epsilon-toxin promoter. When we compared the temperature dependency of gene transcription from epsilon-toxin promoter to those from other bending promoters, alpha-toxin and ferredoxin promoters ; epsilon-toxin, alpha-toxin and ferredoxin promoters exhibit high-level transcription at 37℃, 25℃ and over a wide rangeof temperature, respectively. Thus, we constructed a novel expression vector using ferredoxin promoter to express efficiently large clostridial proteins in C.perfringens. Our expression system was successfully applied to produce large amounts of ColH, NagH, NagJ, NanJ, and BgaA, which are poorly expressed in Escherichia coli expression system. These proteins were purified in sufficient amounts from the supernatants of the recombinant C.perfringens cultures.