Three NADH oxidase encoding genesnoxA-1, noxB-1 andnoxCwere cloned from the genome ofArchaeoglobus fulgidus, expressed inEscherichia coli, and the gene products were purified and characterized. Expression ofnoxA-1and noxB-1resulted in active gene products of the expected size. ThenoxCgene was expressed as well but the protein pro-duced showed no activity in the standardNox assay. NoxA-1 and NoxB-1 are both FAD-containing enzymes with subunit molecular masses of 48 and 69 kDa, respectively.
