A PhoP-regulated outer membrane protease of Salmonella enterica serovar typhimurium promotes resistance to alpha-helical antimicrobial peptides.

ABSTRACT: The outer membrane protein contents of Salmonella enterica serovar Typhimurium strains with PhoP/PhoQ regulon mutations were compared by two-dimensional gel electrophoresis. At least 26 species of outer membrane proteins (OMPs) were identified as being regulated by PhoP/PhoQ activation. One PhoP/PhoQ-activated OMP was identified by semiautomated tandem mass spectrometry coupled with electronic database searching as PgtE, a member of the Escherichia coli OmpT and Yersinia pestis Pla family of outer membrane proteases. Salmonella PgtE expression promoted resistance to alpha-helical cationic antimicrobial peptides (alpha-CAMPs). Strains expressing PgtE cleaved C18G, an 18-residue alpha-CAMP present in culture medium, indicating that protease activity is likely to be the mechanism of OmpT-medi

SUBMITTER: Guina T 

PROVIDER: S-EPMC94595 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature