Identification of a new member of the phage shock protein response in Escherichia coli, the phage shock protein G (PspG).
The phage shock protein operon (pspABCDE) of Escherichia coli is strongly up-regulated in response to overexpression of the filamentous phage secretin protein IV (pIV) and by many other stress conditions including defects in protein export. PspA has an established role in maintenance of the proton-motive force of the cell under stress conditions. Here we present evidence for a new member of the phage shock response in E. coli. Using transcriptional profiling, we show that the synthesis of pIV in E. coli leads to a highly restricted response limited to the up-regulation of the psp operon genes and yjbO. The psp operon and yjbO are also up-regulated in response to pIV in Salmonella enterica serovar Typhimurium. yjbO is a highly conserved gene found exclusively in bacteria that contain a psp operon but is physically unlinked to the psp operon. yjbO encodes a putative inner membrane protein that is co-controlled with the psp operon genes and is predicted to be an effector of the psp response in E. coli. We present evidence that yjbO expression is driven by sigma(54)-RNA polymerase, activated by PspF and integration host factor, and negatively regulated by PspA. PspF specifically regulates only members of the PspF regulon: pspABCDE and yjbO. We found that increased expression of YjbO results in decreased motility of bacteria. Because yjbO is co-conserved and co-regulated with the psp operon and is a member of the phage shock protein F regulon, we propose that yjbO be renamed pspG.
Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
Louise J
LJ
Lloyd
Susan E
SE
Jones
Goran
G
Jovanovic
Prasad
P
Gyaneshwar
Matthew D
MD
Rolfe
Arthur
A
Thompson
Jay C
JC
Hinton
Martin
M
Buck
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001483:Base Sequence; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D016678:Genome; D016680:Genome, Bacterial; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010957:Plasmids / Q000378:metabolism; D011522:Protons; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019779:Salmonella enterica / Q000378:metabolism; D015534:Trans-Activators / Q000502:physiology; D014158:Transcription, Genetic; D015854:Up-Regulation; D001616:beta-Galactosidase / Q000378:metabolism
D001426:Bacterial Proteins; D018076:DNA, Complementary; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D011522:Protons; C098954:PspF protein, E coli; D015534:Trans-Activators; C496547:phage shock protein G, E coli; C069816:phage shock protein, Bacteria; D001616:beta-Galactosidase