Journal article
Effect of Asp122 Mutation on the Hydride Transfer in E. coli DHFR Demonstrates the Goldilocks of Enzyme Flexibility
The journal of physical chemistry. B, Vol.122(33), pp.8006-8017
08/09/2018
DOI: 10.1021/acs.jpcb.8b05556
PMID: 30040418
Abstract
Dihydrofolate reductase (DHFR) catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THF) in the presence of NADPH. The key hydride transfer step in the reaction is facilitated by a combination of enzyme active site preorganization and correlated protein motions in the Michaelis-Menten (E:NADPH:DHF) complex. The present theoretical study employs mutagenesis to examine the relation between structural and functional properties of the enzyme. We mutate Asp122 in Escherichia coli DHFR, which is a conserved amino acid in the DHFR family. The consequent effect of the mutation on enzyme catalysis is examined from an energetic, structural and short-time dynamic perspective. Our investigations suggest that the structural and short-time dynamic perturbations caused by Asp122X mutations (X = Asn, Ser, Ala) are along the reaction coordinate and lower the rate of hydride transfer. Importantly, analysis of the correlated and principle component motions in the enzyme suggest that the mutation alters the coupled motions that are present in the wild-type enzyme. In the case of D122N and D122S, the mutations inhibit coupled motion, whereas in the case of D122A, the mutation enhances coupled motion, although all mutations result in similar rate reduction. These results emphasize a Goldilocks principle of enzyme flexibility, that is, enzymes should neither be too rigid nor too flexible.
Details
- Title: Subtitle
- Effect of Asp122 Mutation on the Hydride Transfer in E. coli DHFR Demonstrates the Goldilocks of Enzyme Flexibility
- Creators
- Anil R Mhashal - Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry , Bar-Ilan University , Ramat-Gan 52900 , IsraelYaron Pshetitsky - Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry , Bar-Ilan University , Ramat-Gan 52900 , IsraelReuven Eitan - Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry , Bar-Ilan University , Ramat-Gan 52900 , IsraelChristopher M Cheatum - Department of Chemistry , University of Iowa , Iowa City , Iowa 52242 , United StatesAmnon Kohen - Department of Chemistry , University of Iowa , Iowa City , Iowa 52242 , United StatesDan Thomas Major - Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry , Bar-Ilan University , Ramat-Gan 52900 , Israel
- Resource Type
- Journal article
- Publication Details
- The journal of physical chemistry. B, Vol.122(33), pp.8006-8017
- DOI
- 10.1021/acs.jpcb.8b05556
- PMID
- 30040418
- NLM abbreviation
- J Phys Chem B
- ISSN
- 1520-6106
- eISSN
- 1520-5207
- Publisher
- American Chemical Society
- Grant note
- DOI: 10.13039/501100001742, name: United States-Israel Binational Science Foundation, award: 2012340; DOI: 10.13039/501100003977, name: Israel Science Foundation, award: 2146/15
- Language
- English
- Date published
- 08/09/2018
- Academic Unit
- Liberal Arts and Science Admin; Chemistry
- Record Identifier
- 9984217459502771
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