PMID:22437714
| Citation |
Loveridge, EJ, Behiry, EM, Guo, J and Allemann, RK (2012) Evidence that a 'dynamic knockout' in Escherichia coli dihydrofolate reductase does not affect the chemical step of catalysis. Nat Chem 4:292-7 |
|---|---|
| Abstract |
The question of whether protein motions play a role in the chemical step of enzymatic catalysis has generated much controversy in recent years. Debate has recently reignited over possible dynamic contributions to catalysis in dihydrofolate reductase, following conflicting conclusions from studies of the N23PP/S148A variant of the Escherichia coli enzyme. By investigating the temperature dependence of kinetic isotope effects, we present evidence that the reduction in the hydride transfer rate constants in this variant is not a direct result of impairment of conformational fluctuations. Instead, the conformational state of the enzyme immediately before hydride transfer, which determines the electrostatic environment of the active site, affects the rate constant for the reaction. Although protein motions are clearly important for binding and release of substrates and products, there appears to be no detectable dynamic coupling of protein motions to the hydride transfer step itself. |
| Links |
PubMed Online version:10.1038/nchem.1296 |
| Keywords |
Biocatalysis; Catalytic Domain; Escherichia coli/enzymology; Kinetics; Mutagenesis, Site-Directed; Protein Structure, Tertiary; Tetrahydrofolate Dehydrogenase/chemistry; Tetrahydrofolate Dehydrogenase/genetics; Tetrahydrofolate Dehydrogenase/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
See also
References
See Help:References for how to manage references in EcoliWiki.