EC 4.2.3.201     
Accepted name: hydropyrene synthase
Reaction: geranylgeranyl diphosphate = hydropyrene + diphosphate
Glossary: hydropyrene = (1R,3aR,3a1R,5aR,5a1S,8aS,10aS)-1,5a,8a-trimethyl-4-methylidenehexadecahydropyrene
Other name(s): HpS
Systematic name: geranylgeranyl-diphosphate diphosphate-lyase (cyclizing, hydropyrene-forming)
Comments: Isolated from the bacterium Streptomyces clavuligerus. The 1-proR hydrogen atom of geranylgeranyl diphosphate is lost in the reaction. The enzyme also produces hydropyrenol, isoelisabethatriene and traces of other diterpenoids. cf. EC 4.2.3.202, hydropyrenol synthase, and EC 4.2.3.203, isoelisabethatriene synthase.
References:
1.  Rinkel, J., Rabe, P., Chen, X., Kollner, T.G., Chen, F. and Dickschat, J.S. Mechanisms of the diterpene cyclases β-pinacene synthase from Dictyostelium discoideum and hydropyrene synthase from Streptomyces clavuligerus. Chem. Eur. J. 23 (2017) 10501–10505. [PMID: 28696553]
[EC 4.2.3.201 created 2019]
 
 
EC 4.2.3.202     
Accepted name: hydropyrenol synthase
Reaction: geranylgeranyl diphosphate + H2O = hydropyrenol + diphosphate
Glossary: hydropyrenol = (1R,3aR,3a1S,4S,5aR,5a1S,8aS,10aS)-1,4,5a,8a-tetramethylhexadecahydropyren-4-ol
Other name(s): HpS
Systematic name: geranylgeranyl-diphosphate diphosphate-lyase (cyclizing, hydropyrenol-forming)
Comments: Isolated from the bacterium Streptomyces clavuligerus. The 1-proR hydrogen atom of geranylgeranyl diphosphate is lost in the reaction. The enzyme also produces hydropyrene, isoelisabethatriene and traces of other diterpenoids. cf. EC 4.2.3.201, hydropyrene synthase, and EC 4.2.3.203, isoelisabethatriene synthase.
References:
1.  Rinkel, J., Rabe, P., Chen, X., Kollner, T.G., Chen, F. and Dickschat, J.S. Mechanisms of the diterpene cyclases β-pinacene synthase from Dictyostelium discoideum and hydropyrene synthase from Streptomyces clavuligerus. Chem. Eur. J. 23 (2017) 10501–10505. [PMID: 28696553]
[EC 4.2.3.202 created 2019]
 
 
EC 4.2.3.203     
Accepted name: isoelisabethatriene synthase
Reaction: geranylgeranyl diphosphate = isoelisabethatriene + diphosphate
Glossary: isoelisabethatriene = (1S,4R)-4,7-dimethyl-1-[(2R)-6-methylhept-5-en-2-yl]-1,2,3,4,5,6-hexahydronaphthalene
Other name(s): HpS (ambiguous)
Systematic name: geranylgeranyl-diphosphate diphosphate-lyase (cyclizing, isoelisabethatriene-forming)
Comments: Isolated from the bacterium Streptomyces clavuligerus. The 1-proR hydrogen atom of geranylgeranyl diphosphate is involved in a 1,3-hydride shift to the side-chain. The enzyme also produces hydropyrene, hydropyrenol, and traces of other diterpenoids. cf. EC 4.2.3.201, hydropyrene synthase, and EC 4.2.3.202, hydropyrenol synthase.
References:
1.  Rinkel, J., Rabe, P., Chen, X., Kollner, T.G., Chen, F. and Dickschat, J.S. Mechanisms of the diterpene cyclases β-pinacene synthase from Dictyostelium discoideum and hydropyrene synthase from Streptomyces clavuligerus. Chem. Eur. J. 23 (2017) 10501–10505. [PMID: 28696553]
[EC 4.2.3.203 created 2019]