Flavohemoprotein involved in nitric oxide (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 protozoan parasite from various noxious nitrogen compounds. Therefore, plays a central role in the inducible response to nitrosative stress. May also be involved in O(2) detoxification. NADPH + 2 nitric oxide + 2 O2 = H(+) + NADP(+) + 2 nitrate NADH + 2 nitric oxide + 2 O2 = H(+) + NAD(+) + 2 nitrate Binds 1 heme b group. Binds 1 FAD. Monomer. Expressed at very low levels in untreated trophozoites of the parasite. Expression is markedly stimulated in nitrite-supplemented medium. Induction by nitrite is probably mediated by NO, likely generated upon reduction of nitrite. Also induced in cells grown in the presence of the NO-donors 3,3-bis(aminoethyl)-1-hydroxy-2-oxo-1-triazene (DETA-NONOate), and S-nitrosoglutathione (GSNO). 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.