PROSITE documentation PDOC50924

MHYT domain profile

The MHYT domain is an about 190-residue domain, which was named after its conserved amino acid pattern. The MHYT domain consists of six predicted transmembrane (TM) segments, connected by short arginine-rich cytoplasmic loops and periplasmic loops that are also rich in charged amino acid residues. Three of its TM segments have a very similar amino acid sequence motif with highly conserved methionine, histidine and tyrosine residues located near the outer face of the cytoplasmic membrane. The MHYT domain has been found in several phylogenetically distant bacteria, either as a separate, single domain protein, or fused to a LytTR-type DNA-binding helix-turn-helix (see <PDOC50930>), or fused to signaling domains, such as histidine kinase (see <PDOC50109>), GGDEF (see <PDOC50887>), EAL (see <PDOC50883>), and PAS (see <PDOC50112>). It has been proposed that the MHYT domain serves as a sensor domain in some bacterial two-component signal transduction systems as well as in a variety of other bacterial proteins. 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 [1].

Some proteins known to contain a MHYT domain are listed below:

• Bacillus subtilis ykoW. It is expressed during logarithmic growth in rich medium.
• Synechocystis sp. sensory transduction histidine kinase slr2098.
• Oligotropha carboxidovorans coxC and coxH proteins.

The profile we developed covers the entire MHYT domain.