CRTI-type phytoene desaturase is an enzyme present in bacteria and fungi. The main role of the enzyme is the conversion of cis-phytoene, a 40-carbon molecule with a single cis bond, into all-trans lycopene. This reaction is a part of carotenoid synthesis. The CRTI gene encoding the enzyme is researched because of its importance in fortifying foods with provitamin A, for example Golden Rice, used to combat vitamin A malnutrition.
Defined by 4 residues: GLU:A-31ARG:A-148ASP:A-149ARG:A-152