Reaction: (2Z,6E)-farnesyl diphosphate = (–)-α-cedrene + diphosphate
Other name(s): EAS3 (gene name); EAS4 (gene name)
Systematic name: (2Z,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, (–)-α-cedrene-forming)
Comments: The enzyme occurs in plants. The initial cyclization product is a (7R)-β-bisabolyl cation. (–)-α-Cedrene is one of the major products. Other products are (+)-2-epi-prezizaene (cf. EC 4.2.3.226, (+)-2-epi-prezizaene synthase), small amounts of (+)-β-curcumene, and other sesquiterpenes with less than 10% yield. The enzyme from Nicotiana tabacum (tobacco) also catalyses the reaction of EC 4.2.3.61, 5-epiaristolochene synthase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Noel, J.P., Dellas, N., Faraldos, J.A., Zhao, M., Hess, B.A., Jr., Smentek, L., Coates, R.M. and O'Maille, P.E. Structural elucidation of cisoid and transoid cyclization pathways of a sesquiterpene synthase using 2-fluorofarnesyl diphosphates. ACS Chem. Biol. 5 (2010) 377-392. [PMID: 20175559]
2. Faraldos, J.A., O'Maille, P.E., Dellas, N., Noel, J.P. and Coates, R.M. Bisabolyl-derived sesquiterpenes from tobacco 5-epi-aristolochene synthase-catalyzed cyclization of (2Z,6E)-farnesyl diphosphate. J. Am. Chem. Soc. 132 (2010) 4281-4289. [PMID: 20201526]