Prolycopene isomerase (, CRTISO, carotene cis-trans isomerase, ZEBRA2 (gene), carotene isomerase, carotenoid isomerase) is an enzyme with systematic name 7,9,7',9'-tetracis-lycopene cis-trans-isomerase. This enzyme catalyses the following chemical reaction
This enzyme is involved in carotenoid biosynthesis.