Is involved in NO detoxification in an aerobic process, termed nitric oxide dioxygenase (NOD) reaction that utilizes O(2) and NAD(P)H to convert NO to nitrate, which protects the bacterium from various noxious nitrogen compounds. Therefore, plays a central role in the inducible response to nitrosative stress. NADPH + 2 nitric oxide + 2 O2 = H(+) + NADP(+) + 2 nitrate NADH + 2 nitric oxide + 2 O2 = H(+) + NAD(+) + 2 nitrate Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit. Binds 1 FAD per subunit. Monomer. By nitric oxide. Consists of two distinct domains; an N-terminal heme-containing oxygen-binding domain and a C-terminal reductase domain with binding sites for FAD and NAD(P)H. Belongs to the globin family. Two-domain flavohemoproteins subfamily. In the C-terminal section; belongs to the flavoprotein pyridine nucleotide cytochrome reductase family.