A single member of the NhaC family, a protein from Bacillus firmus, has been functionally characterized.It is involved in pH homeostasis and sodium extrusion. Members of the NhaC family are found in both Gram-negative bacteria and Gram-positive bacteria. Intriguingly, archaeal homolog ArcD (just outside boundaries of family) has been identified as an arginine/ornithine antiporter. [Transport and binding proteins, Cations and iron carrying compounds]
Jiyao W et al.(2023). "The conserved domain database in 2023.",