EC Number   |
Reaction |
Reference |
|---|
    5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
"flip-flop" mechanism may be involved |
2891 |
| 5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
catalytic mechanism, phenolate binding to the oxyanion hole of ketosteroid isomerase via hydrogen bonding, electrostatic contributions and geometric and electrostatic changes, overview, the KSI reaction involves changes in both geometry and charge distribution as the reaction proceeds from its ground state to its intermediate |
682479 |
| 5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
catalytic mechanism, phenolate binding to the oxyanion hole of ketosteroid isomerase via hydrogen bonding, electrostatic contributions and geometric and electrostatic changes, overview, the KSI reaction involves changes in both geometry and charge distribution as the reaction proceeds from its ground state to its intermediate, Tyr16 and Asp103 are important in catalysis |
682479 |
| 5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
enzyme enhances the coupled motion/hydrogen tunneling contribution to the rate acceleration over the solution reaction |
692767 |
| 5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
mechanism in which the transition state for enolization is dienolate-like, characterized by relatively little proton transfer from Tyr14 in the transition state, and the intermediate in the overall reaction is dienol-like. An alternative mechanism in which the intermediate is stabilized by a short, strong hydrogen bond can also be consistent with the data |
2902 |
| 5.3.3.1 | a 3-oxo-DELTA5-steroid = a 3-oxo-DELTA4-steroid |
two-step reaction first, Asp38 acts as a base, abstracting the 4beta-H atom from C-4 of the steroid to form a dienolate as the intermediate, next, the intermediate is reketonized by proton transfer to the 6beta-position, each step goes through its own transition state, catalytic mechanism, theoretical model involving residues Tyr14, Asp38 and Asp99 |
682871 |
