title: MHYT, a new integral membrane sensor domain.
abstract: MHYT, a new conserved protein domain with a likely signaling function, is described. This domain consists of six transmembrane segments, three of which contain conserved methionine, histidine, and tyrosine residues that are projected to lie near the outer face of the cytoplasmic membrane. In Synechocystis sp. PCC6803, this domain forms the N-terminus of the sensor histidine kinase Slr2098. In Pseudomonas aeruginosa and several other organisms, the MHYT domain forms the N-terminal part of a three-domain protein together with previously described GGDEF and EAL domains, both of which have been associated with signal transduction due to their presence in likely signaling proteins. In Bacillus subtilis YkoW protein, an additional PAS domain is found between the MHYT and GGDEF domains. A ykoW null mutant of B. subtilis did not exhibit any growth alterations, consistent with a non-essential, signaling role of this protein. A model of the membrane topology of the MHYT domain indicates that its conserved residues could coordinate one or two copper ions, suggesting a role in sensing oxygen, CO, or NO.
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA. galperin@ncbi.nlm.nih.gov
authors.forename: M Y
authors.initials: MY
authors.lastname: Galperin
authors.forename: T A
authors.initials: TA
authors.lastname: Gaidenko
authors.forename: A Y
authors.initials: AY
authors.lastname: Mulkidjanian
authors.forename: M
authors.initials: M
authors.lastname: Nakano
authors.forename: C W
authors.initials: CW
authors.lastname: Price
mesh_terms: D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001412:Bacillus subtilis / Q000737:chemistry* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D001419:Bacteria / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D009154:Mutation; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D003300:Copper; D011494:Protein Kinases; D000071677:Histidine Kinase