This group is composed of Citrobacter braakii cytochrome P450cin (P450cin, also called CYP176A1) and similar proteins. P450cin is a bacterial P450 enzyme that catalyzes the enantiospecific hydroxylation of 1,8-cineole to (1R)-6beta-hydroxycineole; its natural reduction-oxidation partner is cindoxin. This family belongs to the large cytochrome P450 (P450, CYP) superfamily of heme-containing proteins that catalyze a variety of oxidative reactions of a large number of structurally different endogenous and exogenous compounds in organisms from all major domains of life. CYPs bind their diverse ligands in a buried, hydrophobic active site, which is accessed through a substrate access channel formed by two flexible helices and their connecting loop.