This domain is often found in association with an NAD-binding region, related to TrkA-N (Pfam:PF02254; personal obs:C. Yeats). XdhC is believed to be involved in the attachment of molybdenum to Xanthine Dehydrogenase ([1]).
This domain is located centrally in BH1974 protein from Alkalihalobacillus halodurans and similar bacterial proteins. It is found C-terminal to Pfam:PF02625 and N-terminal to Pfam:PF13478 and shows an alpha-beta structure.