Article
Hydrogen bonding at the active site of delta 5-3-ketosteroid isomerase.
Biochemistry - 2 Dec 1997
Zhao Q, Abeygunawardana C, Gittis A G, Mildvan A S
Abstract excerpt
The solution secondary structure of the highly active Y55F/Y88F "Tyr-14-only" mutant of delta 5-3-ketosteroid isomerase complexed with 19-nortestosterone hemisuccinate has been shown to consist of three helices, a six-stranded mixed beta-sheet, and five turns. The steroid binds near the general acid, Tyr-14, on helix 1, near the general base, Asp-38, on the first strand of the beta-sheet, and on the hydrophobic...
Topics
- Aspartic Acid
- Binding Sites
- Hydrogen Bonding
- Models, Chemical
- Mutation
- Nuclear Magnetic Resonance, Biomolecular
- Protein Structure, Secondary
- Recombinant Proteins
- Steroid Isomerases
- Tyrosine