Monooxygenase

Monooxygenases are enzymes that incorporate one hydroxyl group into substrates in many metabolic pathways. In this reaction, two atoms of dioxygen are reduced to one hydroxyl group and one H2O molecule by the concomitant oxidation of NAD(P)H.

Classification
According to the Protein Data Bank[3], monooxygenase has not been assigned an EC number, therefore is not an enzyme (stated above), along with the related structures, and is instead, structural. It is classifed as an Oxidoreductase enzyme that catalyzes an electron transfer. The sequence similarity, or family, is known as FAD binding protein (residues 11-388). The compound consists of 1 polymer and 3 ligands (FAD: FLAVIN-ADENINE DINUCLEOTIDE, I7T: 7-IODOTETRACYCLINE, SO4: SULFATE ION).

The monooxygenase protein is composed of 398 amino acid residues, splitting into 4 identical chains, all containing "TetX2 protein". These chains consist of both α-helix, 12 helices characterized by 123 residues and β sheet, 18 pleated sheets characterized between 94-96 residues (See Monooxygenase Chain Display).

Clinical Use
Tigecycline (Tygacil®) is a recently approved antibiotic that involves flavin-dependent monooxygenase TetX. Tygacil® is a method of defense against multidrug-resistant pathogens. The first resistance mechanism against tigecucline is TetX. The crystal structure of (FAD_binding_protein) Tetx monooxygenase is meant to show that TetX-based resistance is extremely versatile prior to what we now know through clinical observations.

Related Structures
2XDO 2XYO 2Y6R

Human proteins containing this domain
COQ6;     MICAL1;    MICAL2;    MICAL2PV1; MICAL2PV2; MICAL3;