Suppressor mutations in alpha-subunit of RNA polymerase for a mutant of the positive regulator, OmpR, in Escherichia coli.
The OmpR protein is a positive regulator specific for the Escherichia coli ompF and ompC genes. This protein functions in a phosphorylation-dependent manner through a presumed interaction with RNA polymerase. We previously isolated OmpR mutants which were suggested to be defective in transcription activation, but not in DNA binding (the so-called positive control (PC) mutant). In this study we isolated mutants of the alpha-subunit of RNA polymerase which can suppress one of the putative PC mutants of OmpR. A crucial amino acid substitution was identified as [V264G] in the alpha-subunit, which is located in the helix H1 of the C-terminal domain, which has been claimed, based on mutational and structural analyses, to be involved in the interaction with other positive regulators including the well-characterized cAMP receptor protein.
Kato
N
N
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Japan.
Aiba
H
H
Mizuno
T
T
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D016153:Genes, Suppressor / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017510:Protein Folding; D017434:Protein Structure, Tertiary
D001425:Bacterial Outer Membrane Proteins; D012321:DNA-Directed RNA Polymerases