Constitutive mutations of the Salmonella enterica serovar Typhimurium transcriptional virulence regulator phoP.

ABSTRACT: The PhoP-PhoQ two-component system is necessary for the virulence of Salmonella spp. and is responsible for regulating several modifications of the lipopolysaccharide (LPS). Mutagenesis of the transcriptional regulator phoP resulted in the identification of a mutant able to activate transcription of regulated genes approximately 100-fold in the absence of PhoQ. Sequence analysis showed two single-base alterations resulting in amino acid changes at positions 93 (S93N) and 203 (Q203R). These mutations were individually created, and although each resulted in a constitutive phenotype, the double mutant displayed a synergistic effect both in the induction of PhoP-activated gene expression and in resistance to antimicrobial peptides. The constitutive phoP gene was placed under the control of an

SUBMITTER: Gunn JS 

PROVIDER: S-EPMC97674 | biostudies-literature | 2000 Jun

REPOSITORIES: biostudies-literature