The PspA protein of Escherichia coli is a negative regulator of sigma(54)-dependent transcription.
In Eubacteria, expression of genes transcribed by an RNA polymerase holoenzyme containing the alternate sigma factor sigma(54) is positively regulated by proteins belonging to the family of enhancer-binding proteins (EBPs). These proteins bind to upstream activation sequences and are required for the initiation of transcription at the sigma(54)-dependent promoters. They are typically inactive until modified in their N-terminal regulatory domain either by specific phosphorylation or by the binding of a small effector molecule. EBPs lacking this domain, such as the PspF activator of the sigma(54)-dependent pspA promoter, are constitutively active. We describe here the in vivo and in vitro properties of the PspA protein of Escherichia coli, which negatively regulates expression of the pspA promoter without binding DNA directly.
Dworkin
J
J
Laboratory of Genetics, The Rockefeller University, New York, New York 10021, USA. dworkin2@fas.harvard.edu
Jovanovic
G
G
Model
P
P
D001426:Bacterial Proteins / Q000302:isolation & purification / Q000502:physiology*; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000502:physiology*; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000302:isolation & purification / Q000502:physiology*; D008565:Membrane Proteins / Q000502:physiology*; D051877:RNA Polymerase Sigma 54; D012808:Sigma Factor / Q000502:physiology*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D012808:Sigma Factor; C069816:phage shock protein, Bacteria; C497751:rpoN protein, E coli; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54