<p>This family includes TorC, a pentahemic c-type cytochrome subunit of periplasmic reductases for trimethylamine-N-oxide (TMAO). The N-terminal half is closely related to tetrahemic NapC (or NirT) subunits of periplasmic nitrate (or nitrite) reductases; some species have both TMAO and nitrate reductase complexes [<cite idref="PUB00015611"/>].</p> Membrane-bound tetrahaem cytochrome TorC/YecK