Evidence map›Paper›PMID 25453098›Full record

ArticleProceedings of the National Academy of Sciences of the United States of America2014

Escherichia coli dihydrofolate reductase catalyzed proton and hydride transfers: temporal order and the roles of Asp27 and Tyr100.

C Tony Liu, Kevin Francis, Joshua P Layfield, Xinyi Huang, Sharon Hammes-Schiffer, Amnon Kohen, Stephen J Benkovic

Open access · bronzeAbstract read
In one paragraph

Article in Proceedings of the National Academy of Sciences of the United States of America, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 35 papers.

0numbers the graph read from it
0cells of the map it votes in
35citing papers in PubMed
3.3field-weighted citation impact, top 7% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

35 citing papers in PubMed, 66 citations in OpenAlex.

  1. Article
  2. Disclosing New Insights on Pyrazolo[3,4-Journal of microbiology and biotechnology · 2025
    Article
  3. A Foundational Shift in Models for Enzyme Function.Journal of the American Chemical Society · 2025
    Review
  4. Article
  5. Review
  6. Article
  7. Perturbative diffraction methods resolve a conformational switch that facilitates a two-step enzymatic mechanism.Proceedings of the National Academy of Sciences of the United States of America · 2024
    Article
  8. Mutexa: A Computational Ecosystem for Intelligent Protein Engineering.Journal of chemical theory and computation · 2023
    Review
  9. Article
  10. Article
  11. Article
  12. Article
  13. Article
  14. Article
  15. Article
  16. Article
  17. Article
  18. Article
  19. Modulating Enzyme FunctionFrontiers in molecular biosciences · 2021
    Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 3 institutions in 1 country.

C Tony LiuDepartment of Chemistry, Pennsylvania State University, University Park, PA 16802;
Kevin FrancisDepartment of Chemistry, The University of Iowa, Iowa City, IA 52242; and.
Joshua P LayfieldDepartment of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801-3364.
Xinyi HuangDepartment of Chemistry, Pennsylvania State University, University Park, PA 16802;
Sharon Hammes-SchifferDepartment of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801-3364.
Amnon KohenDepartment of Chemistry, The University of Iowa, Iowa City, IA 52242; and amnon-kohen@uiowa.edu sjb1@psu.edu.
Stephen J BenkovicDepartment of Chemistry, Pennsylvania State University, University Park, PA 16802; amnon-kohen@uiowa.edu sjb1@psu.edu.
Pennsylvania State University · USUniversity of Illinois Urbana-Champaign · USUniversity of Iowa · US

Funding

Tunneling and dynamic studies with DHFRR01GM065368 · NIGMS · UNIVERSITY OF IOWA · PI CHEATUM, CHRISTOPHER M · 2002 to 2017
$3.5M
Simulation of Proton and Hydride Transfer in EnzymesR37GM056207 · NIGMS · YALE UNIVERSITY · PI HAMMES-SCHIFFER, SHARON · 2011 to 2020
$3.2M
SIMULATION OF PROTON AND HYDRIDE TRANSFER IN ENZYMESR01GM056207 · NIGMS · UNIVERSITY OF NOTRE DAME · PI HAMMES-SCHIFFER, SHARON · 1998 to 2010
$2.7M
Dynamic Properties that Enhance Enzyme FunctionR01GM092946 · NIGMS · ARIZONA STATE UNIVERSITY-TEMPE CAMPUS · PI HECHT, SIDNEY M. · 2010 to 2013
$1.3M
NIGMS NIH HHS GM056207NIGMS NIH HHS GM092946NIGMS NIH HHS GM65368NIGMS NIH HHS R01 GM056207NIGMS NIH HHS R01 GM065368NIGMS NIH HHS R01 GM092946NIGMS NIH HHS R37 GM056207
6 · The paper itself

Abstract

The reaction catalyzed by Escherichia coli dihydrofolate reductase (ecDHFR) has become a model for understanding enzyme catalysis, and yet several details of its mechanism are still unresolved. Specifically, the mechanism of the chemical step, the hydride transfer reaction, is not fully resolved. We found, unexpectedly, the presence of two reactive ternary complexes [enzyme:NADPH:7,8-dihydrofolate (E:NADPH:DHF)] separated by one ionization event. Furthermore, multiple kinetic isotope effect (KIE) studies revealed a stepwise mechanism in which protonation of the DHF precedes the hydride transfer from the nicotinamide cofactor (NADPH) for both reactive ternary complexes of the WT enzyme. This mechanism was supported by the pH- and temperature-independent intrinsic KIEs for the C-H→C hydride transfer between NADPH and the preprotonated DHF. Moreover, we showed that active site residues D27 and Y100 play a synergistic role in facilitating both the proton transfer and subsequent hydride transfer steps. Although D27 appears to have a greater effect on the overall rate of conversion of DHF to tetrahydrofolate, Y100 plays an important electrostatic role in modulating the pKa of the N5 of DHF to enable the preprotonation of DHF by an active site water molecule.

Indexed as

Aspartic AcidBiocatalysisEscherichia coliProtonsTemperatureTetrahydrofolate DehydrogenaseTyrosineAspartic AcidProtonsTetrahydrofolate DehydrogenaseTyrosinedihydrofolate reductasekinetic isotope effectmechanismsynergism

Identifiers

PMID25453098
PMCPMC4280594
OpenAlexW2151019896

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.