Cloning and Initial Characterization of the htrA Gene from Campylobacter Jejuni

Abstract

In response to stress, bacteria upregulate specific groups of proteins which maintain the integrity of the cell; one such protein is HtrA, a serine protease. HtrA production in different bacteria appears to be induced by distinct environmental stress conditions, eg. in Escherichia coli the htrA gene is essential for bacterial survival at high temperatures⁷, whereas a Salmonella typhimurium htrA mutant was temperature insensitive, but susceptible to oxidative stress⁵. A Bruceila abortus htrA mutant is both temperature and oxidative stress sensitive⁴. The HtrA family of stress-response proteins may also be important in bacterial pathogenicity as the S. typhimurium and B. abortus mutants are attenuated for mouse virulence^4,5. The mutant’s susceptibility to oxidative stress suggests increased sensitivity to oxidative killing within macrophages.