| Autor: |
Yabukarski, Filip, Biel, Justin T, Pinney, Margaux M, Doukov, Tzanko, Powers, Alex S, Fraser, James S, Herschlag, Daniel |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| DOI: |
10.1101/786327 |
| Popis: |
Our physical understanding of enzyme catalysis has been limited by the scarcity of data for the positioning and motions of groups in and around the active site. To provide foundational information and test fundamental catalytic models, we created conformational ensembles from 45 PDB crystal structures and collected new ‘room temperature’ X-ray crystallography data for ketosteroid isomerase (KSI). Ensemble analyses indicated substantial pre-positioning and minimal conformational heterogeneity loss through the reaction cycle. The oxyanion hole and general base residues appear conformationally restricted, but not exceptionally so relative to analogous non-catalytic groups. Analysis of surrounding groups and mutant ensembles provide insight into the balance of forces responsible for local conformational preferences. Oxyanion hole catalysis appears to arise from hydrogen bond donors that are stronger than water, without additional catalysis from geometrical discrimination, more distal effects, or environmental alterations. The presence of a range of conformational sub-states presumably facilitates KSI’s multiple reaction steps. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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