Kaurene synthases

Aach, H., Bode, H., Robinson, D.G. and Graebe, J.E. (1997) Ent-kaurene synthase is located in proplastids of meristematic shoot tissues. Planta, 202, 211-9. 

Yamaguchi, S., Saito, T., Abe, H., Yamane, H., Murofushi, N. and Kamiya, Y. (1996) Molecular cloning and characterization of a cDNA encoding the gibberellin biosynthetic enzyme ent-kaurene synthase B from pumpkin (Cucurbita maxima L). Plant., 10, 203-13. 

Yamaguchi, S., Sun, T.P., Kawaide, H. and Kamiya, Y. (1998) The ga2 locus of Arabidopsis thaliana encodes ent-kaurene synthase of gibberellin biosynthesis. Plant Physiol, 116,127-78. 

Fig. 112. Formation of gibberellins from (—)-labdadienyl pyrophosphate 1 Kaurene synthase 2 monooxygenases...

The gibberellin family of compounds, derived from the olefin (-)-kaurene, have been identified in some fungi, and all plants where they function as phytohormones. In plants, (-)-kaurene is formed by two diterpene cyclases working in sequence, copalyl diphosphate synthase (enf-kaurene synthase A or (-)-CPP synthase) and enf-kaurene synthase (enf-kaurene synthase B or (-)-KS). (-)-CPP synthase catalyzes the protonation-initiated cyclization of GGPP to (-)-CPP, while (-)-KS cyclizes (-)-CPP into (-)-kaurene via an ionization-initiated mechanism (see Scheme 18). 

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