MHYT, a new integral membrane sensor domain

FEMS Microbiol Lett. 2001 Nov 27;205(1):17-23. doi: 10.1111/j.1574-6968.2001.tb10919.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence*
  • Anaerobiosis
  • Bacillus subtilis / chemistry*
  • Bacillus subtilis / enzymology*
  • Bacillus subtilis / genetics
  • Bacillus subtilis / growth & development
  • Bacteria / chemistry
  • Bacteria / enzymology
  • Bacteria / genetics
  • Bacteria / growth & development
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Copper / metabolism
  • Histidine Kinase
  • Molecular Sequence Data
  • Mutation
  • Protein Kinases / chemistry*
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Sequence Analysis, DNA
  • Signal Transduction*


  • Bacterial Proteins
  • Copper
  • Protein Kinases
  • Histidine Kinase