Reaction: (2E,6E)-farnesyl diphosphate = (+)-(R)-germacrene A + diphosphate
For diagram of reaction click here.
Other name(s): germacrene A synthase; (+)-germacrene A synthase; (+)-(10R)-germacrene A synthase; GAS; 2-trans,6-trans-farnesyl-diphosphate diphosphate-lyase (germacrene-A-forming); 2-trans,6-trans-farnesyl-diphosphate diphosphate-lyase [(+)-(R)-germacrene-A-forming]
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase [(+)-(R)-germacrene-A-forming]
Comments: Requires Mg2+ for activity. While germacrene A is an enzyme-bound intermediate in the biosynthesis of a number of phytoalexins, e.g. EC 4.2.3.9 (aristolochene synthase) from some species and EC 4.2.3.21 (vetispiradiene synthase), it is the sole sesquiterpenoid product formed in chicory [1].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 213763-55-4
References:
1. Bouwmeester, H.J., Kodde, J., Verstappen, F.W., Altug, I.G., de Kraker, J.W. and Wallaart, T.E. Isolation and characterization of two germacrene A synthase cDNA clones from chicory. Plant Physiol. 129 (2002) 134-144. [PMID: 12011345]
2. Prosser, I., Phillips, A.L., Gittings, S., Lewis, M.J., Hooper, A.M., Pickett, J.A. and Beale, M.H. (+)-(10R)-Germacrene A synthase from goldenrod, Solidago canadensis; cDNA isolation, bacterial expression and functional analysis. Phytochemistry 60 (2002) 691-702. [PMID: 12127586]
3. de Kraker, J.W., Franssen, M.C., de Groot, A., Konig, W.A. and Bouwmeester, H.J. (+)-Germacrene A biosynthesis. The committed step in the biosynthesis of bitter sesquiterpene lactones in chicory. Plant Physiol. 117 (1998) 1381-1392. [PMID: 9701594]
4. Calvert, M.J., Ashton, P.R. and Allemann, R.K. Germacrene A is a product of the aristolochene synthase-mediated conversion of farnesylpyrophosphate to aristolochene. J. Am. Chem. Soc. 124 (2002) 11636-11641. [PMID: 12296728]
5. Chang, Y.J., Jin, J., Nam, H.Y. and Kim, S.U. Point mutation of (+)-germacrene A synthase from Ixeris dentata. Biotechnol. Lett. 27 (2005) 285-288. [PMID: 15834787]