Cytochrome P450 proteins are heme-thiolate monooxygenases that mediate NADPH-dependent electron transport and function to oxidize a variety of structurally unrelated compounds, including steroids, fatty acids and xenobiotics. Specifically, Cytochrome P450s are responsible for metabolizing arachidonic acid to hydroxyeicosatetraenoic acid (a regulator of blood pressure) and epoxyeicosatrienoic acid (a molecule involved in signaling events). CYP20A1 (cytochrome P450, family 20, subfamily A, polypeptide 1), also known as CYP-M, is a 462 amino acid single-pass membrane protein that belongs to the cytochrome P450 family. CYP20A1 is thought to carry its own oxygen as it lacks a conserved I-helix motif and one amino acid of its conserved heme binding site.