  4.2.3.53 | (2Z,6Z)-farnesyl diphosphate |
involved in sesquiterpene biosynthesis. The enzyme synthesizes a mixture of sesquiterpenoids from (2Z,6Z)-farnesyl diphosphate. Following dephosphorylation of (2Z,6Z)-farnesyl diphosphate, the (2Z,6Z)-farnesyl carbocation is converted to either the (6R)- or the (6S)-bisabolyl cations depending on the stereochemistry of the 6,1 closure. The (6R)-bisabolyl cation will then lead to the formation of (+)-alpha-santalene, while the (6S)-bisabolyl cation will give rise to (-)-endo-alpha-bergamotene and (+)-endo-beta-bergamotene. Small amounts of (-)-epi-beta-santalene are also formed from the (6R)-bisabolyl cation and small amounts of (-)-exo-alpha-bergamotene are formed from the (6S)-bisabolyl cation |
Solanum habrochaites |
(+)-endo-beta-bergamotene + diphosphate |
- |
? |
| 4.2.3.53 | (2Z,6Z)-farnesyl diphosphate |
because (2Z,6Z)-farnesyl diphosphate is not commercially available, in vitro enzymatic assays with both (2Z,6Z)-farnesyl diphosphate synthase and and SBS recombinant proteins are conducted using isopentenyl diphosphate and dimethylallyl diphosphate as substrates. No activity with geranyl diphosphate, (2E,6E)-farnesyl diphosphate, and (2E,6E,10E)-geranylgeranyl diphosphate. Multiproduct cyclization pathway for the cyclization of (2Z,6Z)-farnesyl diphosphate to class II sesquiterpenes by SBS: following dephosphorylation of (2Z,6Z)-farnesyl diphosphate, the (2Z,6Z)-farnesyl carbocation is converted to either the (6R)- or the (6S)-bisabolyl cations depending on the stereochemistry of the 6,1 closure. The (6R)-bisabolyl cation will then lead to the formation of (+)-alpha-santalene and (-)-epi-beta-santalene, while the (6S)-bisabolyl cation will give rise to (-)-exo-alpha-bergamotene, (-)-endo-alpha-bergamotene, and (+)-endo-beta-bergamotene |
Solanum habrochaites |
(+)-endo-beta-bergamotene + diphosphate |
- |
? |
