Heme-binding sensor kinase component part of a two-component regulatory system involved in methyl sulfide metabolism. Does not act as a phytochrome-like photoreceptor. ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Heme-binding is redox-active and coordinates various ligands such as imidazole, dimethyl sulfide, and carbon monoxide depending on the redox state. The redox state of the heme cofactor influences on autophosphorylation activity: while reduced protein does not autophosphorylate, oxidized protein promotes autophosphorylation signal. Autophosphorylates: autophosphorylation is dependent on the redox state of heme cofactor and is promoted upon reduction. Cells constitutively synthesize MtsF.