Members of this largely archaeal protein family are subunit A of the formylmethanofuran dehydrogenase. Nomenclature in some bacteria may reflect inclusion of the formyltransferase described by TIGR03119 as part of the complex, and therefore call this protein formyltransferase/hydrolase complex Fhc subunit A. Note that this model does not distinguish tungsten (FwdA) from molybdenum-containing (FmdA) forms of this enzyme; a single gene from this family is expressed constitutively in Methanobacterium thermoautotrophicum, which has both tungsten and molybdenum forms and may work interchangeably.
Jiyao W et al.(2023). "The conserved domain database in 2023.",