Characterization and sequence of the Escherichia coli stress-induced psp operon.
We describe a new Escherichia coli operon, the phage shock protein (psp) operon, which is induced in response to heat, ethanol, osmotic shock and infection by filamentous bacteriophages. The operon includes at least four genes: pspA, B, C and E. PspA associates with the inner membrane and has the heptad repeats characteristic of proteins that can form coiled coils. The operon encodes a factor that activates psp expression, and deletion analyses indicate that this protein is PspC; PspC is predicted to possess a leucine zipper, a motif present in many eukaryotic transcription factors. The pspE gene is expressed in response to stress as part of the operon, but is also transcribed from its own promoter under normal conditions. In vitro studies suggest that PspA and C are modified in vivo. Expression of the psp genes does not require the heat shock sigma factor, sigma32. The increased duration of psp induction in a sigma32 mutant suggests that a product (or products) of the heat shock response down-regulates expression of the operon.
Brissette
J L
JL
Rockefeller University, New York, NY 10021.
Weiner
L
L
Ripmaster
T L
TL
Model
P
P
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D003090:Coliphages / Q000235:genetics / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005838:Genotype; D006360:Heat-Shock Proteins / Q000235:genetics*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009876:Operon; D012329:RNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D015534:Trans-Activators / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D015345:Oligonucleotide Probes; C569033:PspC protein, E coli; D012329:RNA, Bacterial; D015534:Trans-Activators; C069816:phage shock protein, Bacteria