EC Number   |
General Information |
Reference |
|---|
    4.2.3.146 | evolution |
the enzyme belongs to the class I terpene cyclases |
-, 746593 |
| 4.2.3.146 | metabolism |
the enzyme is involved in biosynthesis of cyclooctatin |
-, 747495, 747560 |
| 4.2.3.146 | more |
class I terpene cyclases contain two conserved motifs, DDXXD and (N,D)XX(S,T)XXX(E,D), in which residues cooperate to coordinate to the three bound Mg2+ ions that themselves bind and orient the substrate through its diphosphate moiety while facilitating the ionization of the C-O bond of the allylic diphosphate substrate, thereby initiating the cyclization cascade by the generation of a highly reactive carbocation intermediate. CotB2 has an unusual aspartate-rich motif (110DDMD), in which the interval between the second and third aspartate residues is only one residue, whereas typical terpene cyclases have two (DDXXD) or three (DDXXXD) intervening residues. The NSE/DTE motif (220NDFYSYDRE), which is involved in binding Mg2+ ions in class I terpene cyclases, is located opposite the aspartate-rich motif at the upper rim of the CotB2 active site. Stucture-function relationship, overview |
-, 746593 |
| 4.2.3.146 | physiological function |
the diterpene cyclase CotB2 catalyzes the cyclization of acyclic geranylgeranyl diphosphate (GGPP) to produce tricyclic (2R,3R,6R,7S,11R,14R)-cyclooctat-9-en-7-ol, which is characterized by a 5-8-5-fused ring skeleton and constitutes the carbon framework of a potent lisophospholipase inhibitor, cyclooctatin. Proposal of a cyclization cascade involving a unique carbon-carbon bond rearrangement combined with multiple hydride shifts, all occurring at a single active site. The enzyme exhibits effective control of ring formation and stereochemistry during CotB2 catalysis |
-, 746593 |
| 4.2.3.146 | physiological function |
the enzyme catalyzes the formation of cyclooctat-9-en-7-ol, which is a precursor of cyclooctatin, a diterpene with a unique tricyclic diterpene skeleton characterized by a 5-8-5 fused-ring system, which is a potent inhibitor of lysophospholipase, an enzyme that catalyzes the hydrolysis of the fatty acid ester bonds of lysophospholipids |
-, 746744 |
