Response of universal stress protein from Streptomyces lividans 1326 to oxidative stress

Abstract:

[Objective] Universal stress protein (USP) belongs to an ancient protein family. In Streptomyces, its physiological function has not been reported yet. This work focused on the protein particularly. [Methods] Sequence alignment was performed. The association between cAMP and USP was detected using circular dichroism spectroscopy. The usp gene (SLI_7517) was also disrupted. Susceptibility of wild-type and the usp disruption mutant strains to the thiol oxidant, diamide, was analyzed. qPCR was conducted to detect the expression differences of glutathione peroxidase and thiol peroxidase genes between the wild-type and usp disruption mutant strains. [Results] USP from different Streptomyces species shares 90% similarity, with the highly conserved USP-like domain. The alteration of USP CD spectra was observed when USP was mixed with cAMP. Tolerance to diamide increased after usp was knocked out. The transcription level of glutathione peroxidase gene was up-regulated in the usp disruption mutant. [Conclusion] USP protein from Streptomyces lividans 1326 can bind to cAMP. It might be involved in the regulation process, that suppresses the transcription of glutathione peroxidase when the bacteria exposed to oxidative environment.