title: The SixA phospho-histidine phosphatase modulates the ArcB phosphorelay signal transduction in Escherichia coli.
abstract: The Escherichia coli SixA protein is the first discovered prokaryotic phospho-histidine phosphatase, which was implicated in a His-to-Asp phosphorelay. The sixA gene was originally identified as the one that interferes with, at its multi-copy state, the cross-phosphorelay between the histidine-containing phosphotransmitter (HPt) domain of the ArcB anaerobic sensor and its non-cognate OmpR response regulator. Nevertheless, no evidence has been provided that the SixA phosphatase is indeed involved in a signaling circuitry of the authentic ArcB-to-ArcA phosphorelay in a physiologically meaningful manner. In this study, a SixA-deficient mutant was characterized with special reference to the ArcB signaling, which allows E. coli cells to respond to not only external oxygen, but also certain anaerobic respiratory conditions. Here evidence is provided for the first time that the SixA phosphatase is a crucial regulatory factor that is involved in the ArcB signaling, particularly, under certain anaerobic respiratory growth conditions. We propose a novel mechanism, involving an HPt domain and a phospho-histidine phosphatase, by which a given multi-step His-to-Asp signaling can be modulated.
authors.affiliation: Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku, Nagoya, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D000693:Anaerobiosis; D001224:Aspartic Acid / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000378:metabolism / Q000494:pharmacology; D004579:Electron Transport / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D005650:Fumarates / Q000378:metabolism / Q000494:pharmacology; D005798:Genes, Bacterial / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D006639:Histidine / Q000378:metabolism; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008744:Methylamines / Q000378:metabolism / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012097:Repressor Proteins; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D005650:Fumarates; D008565:Membrane Proteins; D008744:Methylamines; D009566:Nitrates; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C041610:arcA protein, E coli; D001224:Aspartic Acid; D006639:Histidine; C032005:fumaric acid; D011494:Protein Kinases; C065271:arcB protein, E coli; C005855:trimethyloxamine; D010100:Oxygen; D004121:Dimethyl Sulfoxide