:Monooxygenase

{{Pfam_box

| Symbol = FAD_binding_3

| Name = Monooxygenase

| image = 2Y6Q.jpg

| width =

| caption = Structure of the TetX monooxygenase in complex with the substrate 7-Iodtetracycline.{{PDB|2Y6Q}}; {{cite journal | vauthors = Volkers G, Palm GJ, Weiss MS, Wright GD, Hinrichs W | title = Structural basis for a new tetracycline resistance mechanism relying on the TetX monooxygenase | journal = FEBS Lett. | volume = 585 | issue = 7 | pages = 1061–6 |date=April 2011 | pmid = 21402075 | doi = 10.1016/j.febslet.2011.03.012 | s2cid = 26967337 | doi-access = free }}

| Pfam= PF01494

| InterPro= IPR002938

| SMART=

| Prosite =

| SCOP = 2phh

| TCDB =

| OPM family=

| OPM protein=

}}

Monooxygenases are enzymes that incorporate one hydroxyl group (−OH) into substrates in many metabolic pathways. In this reaction, the two atoms of dioxygen are reduced to one hydroxyl group and one H₂O molecule by the concomitant oxidation of NAD(P)H.{{cite journal |vauthors =Harayama S, Kok M, Neidle EL |title=Functional and evolutionary relationships among diverse oxygenases |journal=Annu. Rev. Microbiol. |volume=46 |pages=565–601 |year=1992 |pmid=1444267 |doi=10.1146/annurev.mi.46.100192.003025}}{{cite journal |vauthors=Schreuder HA, van Berkel WJ, Eppink MH, Bunthol C |title=Phe161 and Arg166 variants of p-hydroxybenzoate hydroxylase. Implications for NADPH recognition and structural stability |journal=FEBS Lett. |volume=443 |issue=3 |pages=251–255 |year=1999 |pmid=10025942 |doi=10.1016/S0014-5793(98)01726-8|s2cid=21305517 |doi-access= }} One important subset of the monooxygenases, the cytochrome P450 omega hydroxylases, is used by cells to metabolize arachidonic acid (i.e. eicosatetraenoic acid) to the cell signaling molecules, 20-hydroxyeicosatetraenoic acid or to reduce or totally inactivate the activate signaling molecules for example by hydroxylating leukotriene B4 to 20-hydroxy-leukotriene B5, 5-hydroxyeicosatetraenoic acid to 5,20-dihydroxyeicosatetraenoic acid, 5-oxo-eicosatetraenoic acid to 5-oxo-20-hydroxyeicosatetraenoic acid, 12-hydroxyeicosatetraenoic acid to 12,20-dihydroxyeicosatetraenoic acid, and epoxyeicosatrienoic acids to 20-hydroxy-epoxyeicosatrienoic acids.