Autogenous control of PspF, a constitutively active enhancer-binding protein of Escherichia coli.

Escherichia coli sigma54-dependent phage shock protein operon (pspA to -E) transcription is under the control of PspF, a constitutively active activator. Sigma70-dependent transcription of pspF is under autogenous control by wild-type PspF but not by a DNA-binding mutant, PspF deltaHTH. Negative autoregulation of PspF is continual and not affected by stimuli, like f1 pIV, that induce the pspA to -E operon. PspF production is independent of PspA (the negative regulator of the pspA to -E operon) and of PspB and -C (positive regulators).