Lycopene beta-cyclase explained

Lycopene β-cyclase
Ec Number:	5.5.1.19
Cas Number:	220801-82-1

Lycopene β-cyclase (CrtL, CrtL-b, CrtY) is an enzyme with systematic name carotenoid beta-end group lyase (decyclizing).^{[1] [2] [3] [4] [5] [6]} This enzyme catalyses the following chemical reaction

carotenoid ψ-end group

\rightleftharpoons carotenoid β-end group

This enzyme requires NAD(P)H. It converts Lycopene (2 ψ ends) into β-carotene (2 β ends).

Notes and References

1. Cunningham FX, Chamovitz D, Misawa N, Gantt E, Hirschberg J . Cloning and functional expression in Escherichia coli of a cyanobacterial gene for lycopene cyclase, the enzyme that catalyzes the biosynthesis of beta-carotene . FEBS Letters . 328 . 1–2 . 130–8 . August 1993 . 8344419 . 10.1016/0014-5793(93)80980-9 . 86704801 . Daniel_Chamovitz . free .
2. Cunningham FX, Sun Z, Chamovitz D, Hirschberg J, Gantt E . Molecular structure and enzymatic function of lycopene cyclase from the cyanobacterium Synechococcus sp strain PCC7942 . The Plant Cell . 6 . 8 . 1107–21 . August 1994 . 7919981 . 160505 . 10.1105/tpc.6.8.1107 . 3869889 .
3. Hugueney P, Badillo A, Chen HC, Klein A, Hirschberg J, Camara B, Kuntz M . Metabolism of cyclic carotenoids: a model for the alteration of this biosynthetic pathway in Capsicum annuum chromoplasts . The Plant Journal . 8 . 3 . 417–24 . September 1995 . 7550379 . 10.1046/j.1365-313x.1995.08030417.x . free .
4. Pecker I, Gabbay R, Cunningham FX, Hirschberg J . Cloning and characterization of the cDNA for lycopene beta-cyclase from tomato reveals decrease in its expression during fruit ripening . Plant Molecular Biology . 30 . 4 . 807–19 . February 1996 . 8624411 . 10.1007/bf00019013 . 10470698 .
5. Hornero-Méndez D, Britton G . Involvement of NADPH in the cyclization reaction of carotenoid biosynthesis . FEBS Letters . 515 . 1–3 . 133–6 . March 2002 . 11943208 . 10.1016/s0014-5793(02)02453-5 . 25408239 .
6. Maresca JA, Graham JE, Wu M, Eisen JA, Bryant DA . Identification of a fourth family of lycopene cyclases in photosynthetic bacteria . Proceedings of the National Academy of Sciences of the United States of America . 104 . 28 . 11784–9 . July 2007 . 17606904 . 1905924 . 10.1073/pnas.0702984104 . free .