Transcriptional regulation of Salmonella virulence: a PhoQ periplasmic domain mutation results in increased net phosphotransfer to PhoP.
A mutation in the phoP/phoQ locus (pho-24) that results in unregulated expression of PhoP-activated genes (phenotype PhoP constitutive [PhoP(c)]) was mapped to phoQ. Change of a Thr to Ile at position 48 of PhoQ was responsible for the PhoP(c) phenotype (attenuation of mouse virulence, defects in epithelial cell invasion, and macrophage spacious phagosome formation). PhoP phosphorylation by membrane extracts required PhoQ, and PhoQ Ile-48-containing membranes demonstrated increased net phosphorylation of PhoP.
Department of Medicine, University of Washington, Seattle 98195, USA.
J S
JS
Gunn
E L
EL
Hohmann
S I
SI
Miller
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012475:Salmonella / Q000235:genetics* / Q000472:pathogenicity; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014774:Virulence
D001426:Bacterial Proteins; C079792:PhoQ protein, Bacteria; D014157:Transcription Factors; C061064:PhoP protein, Bacteria