Ent-kaurene synthase explained

ent-kaurene synthase
Ec Number:	4.2.3.19
Cas Number:	9055-64-5
Go Code:	0009899

The enzyme ent-kaurene synthase (EC 4.2.3.19) catalyzes the chemical reaction

ent-copalyl diphosphate

\rightleftharpoons ent-kaurene + diphosphate

This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on phosphates. The systematic name of this enzyme class is ent-copalyl-diphosphate diphosphate-lyase (cyclizing, ent-kaurene-forming). Other names in common use include ent-kaurene synthase B, ent-kaurene synthetase B, ent-copalyl-diphosphate diphosphate-lyase, and (cyclizing). This enzyme participates in diterpenoid biosynthesis.

In Stevia

In Stevia spp., ent-kaurene synthase is a required part of the biosynthesis of steviol.^{[1] [2]} Hajihashemi et al., 2013 find that it is involved in the drought stress response and because it mimics drought stress paclobutrazol toxicity. Both inhbit transcription of steviol glycoside synthesis genes including ent-kaurene synthase. This is believed to reduce steviol content in the final plant product.

References

• Fall RR, West CA . 1971 . Purification and properties of kaurene synthetase from Fusarium moniliforme . J. Biol. Chem. . 246 . 6913 - 28 . 4331199 . 22 .
• Yamaguchi S, Saito T, Abe H, Yamane H, Murofushi N, 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 J. . 10 . 203 - 13 . 8771778 . 10.1046/j.1365-313X.1996.10020203.x . 2 .
• Kawaide H, Imai R, Sassa T, Kamiya Y . 1997 . Ent-kaurene synthase from the fungus Phaeosphaeria sp. L487. cDNA isolation, characterization, and bacterial expression of a bifunctional diterpene cyclase in fungal gibberellin biosynthesis . J. Biol. Chem. . 272 . 21706 - 12 . 9268298 . 10.1074/jbc.272.35.21706 . 35 . free .
• W, Sassa T . 2000 . Cloning of a full-length cDNA encoding ent-kaurene synthase from Gibberella fujikuroi: functional analysis of a bifunctional diterpene cyclase . Biosci. Biotechnol. Biochem. . 64 . 660 - 4 . 10803977 . 10.1271/bbb.64.660 . Kawaide . H . Ishizaki . A . Shinoda . S . Otsuka . M . Mitsuhashi . W . Sassa . T . 3 . free .

Notes and References

1. Zhou . Xuan . Gong . Mengyue . Lv . Xueqin . Liu . Yanfeng . Li . Jianghua . Du . Guocheng . Liu . Long . Metabolic engineering for the synthesis of steviol glycosides: current status and future prospects . . . 105 . 13 . 2021 . 0175-7598 . 10.1007/s00253-021-11419-3 . 5367–5381.
2. Book: Hajihashemi, Shokoofeh . Steviol Glycosides . Agronomic practices . . 2021 . 10.1016/b978-0-12-820060-5.00002-9 . 31–56.