EC Number   |
Reaction |
Reference |
|---|
    5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
- |
- |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
cyclization pathway of (3S)-2,3-oxidosqualene to generate beta-amyrin triterpene via bicyclic, malabaricanyl, dammarenyl, baccharenyl, lupanyl, and oleanyl cation intermediates, detailed mechanism overview |
748805 |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
cyclization pathway of (3S)-2,3-oxidosqualene to generate beta-amyrin triterpene. (3S)-2,3-oxidosqualene is folded into a chair-chair-chair-boat-boat conformation in the enzyme cavity, and the proton released from the DCTA amino acid motif attacks the epoxide ring, leading to sequential ring-forming reactions and the construction of 6,6,6,6,6-fused pentacyclic ring scaffold via several carbocationic intermediates. The oleanyl cation undergoes rearrangement reactions of 1,2-hydride shifts and deprotonation of axial-oriented H-12 to yield beta-amyrin |
747546 |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
molecular substrate docking and catalytic reaction mechanism analysis, overview. Residue Y560 is responsible for the high catalytic efficiency of enzyme GsAS2 compared to GsAS1 |
749323 |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
no scrambling of methyl groups is observed during beta-amyrin formation, the isopropyl group of the lupenyl cation intermediate must be held tightly during product formation |
683580 |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
substrate is used in chair-chair-chair-boat conformation. Cyclization first generates the tetracyclic dammarenyl C20 cation with the 17beta-side chain |
683583 |
| 5.4.99.39 | (3S)-2,3-epoxy-2,3-dihydrosqualene = beta-amyrin |
the Phe416 residue is located near the D-ring formation site and works to position the oxidosqualene substrate correctly within the reaction cavity. On the other hand, the major catalysis-related function of the Tyr259 and Trp257 residues is to yield their Pi-electrons to the cationic intermediate |
748812 |
