MauM ferredoxin-type protein is involved in methylamine utilization []. NapG ferredoxin-type protein is associated with nitrate reductase activity []. The two proteins are highly similar.
Most members of this family are the NapH protein, found next to NapG in operons that encode the periplasmic nitrate reductase [, ]. Some species with this reductase lack NapC but accomplish electron transfer to NapAB in some other manner, likely to involve NapH, NapG, and/or some other protein. A few members of this protein are designated MauN and are found in methylamine utilization operons in species that appear to lack a periplasmic nitrate reductase [].
