Spheroidene monooxygenase explained

Spheroidene monooxygenase
Ec Number:	1.14.15.9

Spheroidene monooxygenase (CrtA, acyclic carotenoid 2-ketolase, spirilloxantin monooxygenase, 2-oxo-spirilloxanthin monooxygenase) is an enzyme with systematic name spheroidene, reduced-ferredoxin:oxygen oxidoreductase (spheroiden-2-one-forming).^{[1] [2]} This enzyme catalyses the following chemical reaction

spheroidene + reduced ferredoxin + O₂

\rightleftharpoons spheroiden-2-one + oxidized ferredoxin + H₂O

spirilloxantin + reduced ferredoxin + O₂

\rightleftharpoons 2-oxospirilloxanthin + oxidized ferredoxin + H₂O

2'-oxospirilloxanthin + reduced ferredoxin + O₂

\rightleftharpoons 2,2'-dioxospirilloxanthin + oxidized ferredoxin + H₂O

The enzyme is involved in spheroidenone biosynthesis and in 2,2'-dioxospirilloxanthin biosynthesis.

Notes and References

1. Lee PC, Holtzapple E, Schmidt-Dannert C . Novel activity of Rhodobacter sphaeroides spheroidene monooxygenase CrtA expressed in Escherichia coli . Applied and Environmental Microbiology . 76 . 21 . 7328–31 . November 2010 . 20851979 . 2976243 . 10.1128/AEM.01606-10 .
2. Gerjets T, Steiger S, Sandmann G . Catalytic properties of the expressed acyclic carotenoid 2-ketolases from Rhodobacter capsulatus and Rubrivivax gelatinosus . Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids . 1791 . 2 . 125–31 . February 2009 . 19136077 . 10.1016/j.bbalip.2008.12.006 .