title: Two new members of the OmpR superfamily detected by homology to a sensor-binding core domain.
abstract: The OmpR superfamily includes proteins that act as transcriptional regulators of operons that respond to environmental stimuli. A homologous domain near the N-terminus, termed a sensor-binding core domain, is thought to play a role in recognition of a signal transduction protein. We have identified two previously unrecognized members of this regulator family of proteins: a 23.8-kd protein transcribed from the uvrC transcription unit and the PgtA gene product, which is a phosphoglycerate transport regulatory protein. The sensor-binding core domain is also present in four proteins that regulate bacterial sporulation and chemotaxis. The 23.8-kd protein also has sequence similarity to elongation factor Tu and two regulatory proteins: HtpR, the heat-shock regulatory protein, and TraJ, a regulator of expression of genes involved in conjugation. There is a 77-amino acid region near the C-terminus of the 23.8-kd protein that has 30% similarity with a 28.1-kd protein coded for by an open reading frame 5' to the reading frame of the 23.8-kd protein in the uvrC transcription unit. Genetic distance analysis of amino acid sequences of proteins with a sensor-binding core domain suggests that the 23.8-kd protein and the chemotaxis regulatory proteins are distantly related to the other regulatory proteins in the OmpR superfamily.
authors.affiliation: Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: T L
authors.initials: TL
authors.lastname: Timme
authors.forename: C B
authors.initials: CB
authors.lastname: Lawrence
authors.forename: R E
authors.initials: RE
authors.lastname: Moses
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004755:Enterobacteriaceae / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D012486:Salmonella typhimurium / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins