Momilactone-A synthase explained

Momilactone-A synthase
Ec Number:	1.1.1.295

Momilactone-A synthase (momilactone A synthase, OsMAS) is an enzyme with systematic name 3beta-hydroxy-9beta-pimara-7,15-diene-19,6beta-olide:NAD(P)⁺ oxidoreductase.^{[1] [2]} This enzyme catalyses the following chemical reaction

3beta-hydroxy-9beta-pimara-7,15-diene-19,6beta-olide + NAD(P)⁺

\rightleftharpoons momilactone A + NAD(P)H + H⁺

The rice phytoalexin momilactone A is a diterpenoid secondary metabolite that is involved in the defense mechanism of the plant. Momilactone A is produced in response to attack by a pathogen through the perception of elicitor signal molecules such as chitin oligosaccharide, or after exposure to UV irradiation.

Notes and References

1. Atawong A, Hasegawa M, Kodama O . Biosynthesis of rice phytoalexin: enzymatic conversion of 3beta-hydroxy-9beta-pimara-7,15-dien-19,6beta-olide to momilactone A . Bioscience, Biotechnology, and Biochemistry . 66 . 3 . 566–70 . March 2002 . 12005050 . 10.1271/bbb.66.566 . 83339044 . free .
2. Shimura K, Okada A, Okada K, Jikumaru Y, Ko KW, Toyomasu T, Sassa T, Hasegawa M, Kodama O, Shibuya N, Koga J, Nojiri H, Yamane H . Identification of a biosynthetic gene cluster in rice for momilactones . The Journal of Biological Chemistry . 282 . 47 . 34013–8 . November 2007 . 17872948 . 10.1074/jbc.M703344200 . free .