EC Number   |
Protein Variants |
Reference |
|---|
   4.2.3.9 | more |
the replacement of Trp 334 with para-substituted phenylalanines of increasing electron-withdrawing properties leads to a progressive accumulation of germacrene A that shows a good correlation with the interaction energies of simple cations such as Na+ with substituted benzenes. Evidence for the stabilizing role played by Trp334 in aristolochene synthase catalysis for the energetically demanding transformation of germacrene A to eudesmane cation. Replacement of tryptophan by para-substituted phenylalanines with strong electron-withdrawing substituents has only minor effects on the KM values of the reaction but leads to approximately 30fold decreases of kcat relative to mutant W334F. Noncanonical substitutions lead to the following ratios of products: W334naphthyl 78% aristolochene, 22% germacrene A, W334-p-chlorophenylalanine or W334-p-fluorophenylalanine 57% aristolochene, 43% germacrene A, W334-p-trifluoromethylphenylalanine 31% aristolochene, 69% germacrene A, W334-p-nitrophenylalanine 23% aristolochene, 77% germacrene A |
715288 |
| 4.2.3.9 | Y92A |
turnover number is approximately 2 orders of magnitude lower than the value observed for the wild-type enzyme,the mutant enzyme produces almost 80% of the alicyclic sesquiterpenes (E)-beta-farnesene and (E,E)-alpha-farnesene. The mutant also produces small amounts of additional hydrocarbons with a molecular weight of 204: alpha-selinene, beta-selinene, selina-4,11-diene, (E,Z)-alpha-farnesene, and beta-bisabolene. Km-value for trans, trans-farnesyl diphosphate is 0.0834 mM compared to 0.0023 mM for the wild-type enzyme |
644243 |
| 4.2.3.9 | Y92C |
turnover number is approximately 2 orders of magnitude lower than the value observed for the wild-type enzyme. Km-value for trans, trans-farnesyl diphosphate is 0.05027 mM compared to 0.0023 mM for the wild-type enzyme |
644243 |
| 4.2.3.9 | F178V |
wild-type enzyme produces 92% aristolochene, 8% germacrene and a small amount of valencene. Mutant enzyme produces 10.8% aristolochene, 54.1% germacrene, 5.2% valencene, 5.7% alpha-selinene, 9.1% beta-selinine, 9.2% (E)-beta-farnesene and 2.7% (E,E)-alpha-farnesene. kcat is 1429fold lower than wild-type value, Km-value is 4.9fold higher than wild-type value |
664584 |
| 4.2.3.9 | F178Y |
wild-type enzyme produces 92% aristolochene, 8% germacrene and a small amount of valencene. Mutant enzyme produces 86.4% aristolochene, 10.7% germacrene, and 2.7% valencene. kcat is 30fold lower than wild-type value, Km-value is 2.2fold higher than wild-type value |
664584 |
