9EJ4
Rat cytosolic PEPCK in complex with GTP and beta-sulfopyruvate (273K)
Summary for 9EJ4
| Entry DOI | 10.2210/pdb9ej4/pdb |
| Descriptor | Phosphoenolpyruvate carboxykinase, cytosolic [GTP], MANGANESE (II) ION, SULFOPYRUVATE, ... (5 entities in total) |
| Functional Keywords | inhibitor complex, metabolic enzyme, multi-temperature, ambient temperature, lyase |
| Biological source | Rattus norvegicus (Norway rat) |
| Total number of polymer chains | 1 |
| Total formula weight | 70355.78 |
| Authors | McLeod, M.J.,Barwell, S.A.E.,Holyoak, T.,Thorne, R.E. (deposition date: 2024-11-27, release date: 2025-04-09) |
| Primary citation | McLeod, M.J.,Barwell, S.A.E.,Holyoak, T.,Thorne, R.E. A structural perspective on the temperature dependent activity of enzymes. Structure, 2025 Cited by PubMed Abstract: Enzyme activity varies with temperature. Unlike small-molecule catalysts, the structural ensembles of enzymes can change substantially with temperature, but it is unclear how this modulates temperature dependent activity. Here, multi-temperature X-ray crystallography was used to record structural changes from -20°C to 40°C for a mesophilic enzyme in complex with inhibitors mimicking substrate-, intermediate-, and product-bound states, representative of major complexes on the reaction coordinate. Inhibitors, substrates and active site loops increasingly populated catalytically competent conformations as temperature increased. These changes occurred even in temperature ranges where kinetic measurements showed roughly linear Arrhenius/Eyring behavior, where parameters characterizing the system are assumed to be temperature independent. Simple analysis shows that linear Arrhenius/Eyring behavior can still be observed when the underlying activation energy/enthalpy values vary with temperature. Our results indicate a critical role for temperature dependent atomic-resolution structural data in interpreting temperature dependent kinetic data from enzymatic systems. PubMed: 40120576DOI: 10.1016/j.str.2025.02.013 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.74 Å) |
Structure validation
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