DOI: 10.1126/science.3511529. Functional Role of Aspartic Acid-27 in Dihydrofolate Reductase Revealed by Mutagenesis

Functional Role of Aspartic Acid-27 in Dihydrofolate Reductase Revealed by Mutagenesis

10.1126/science.3511529

Crossref journal-article

American Association for the Advancement of Science (AAAS)

Science (221)

Abstract

The crystal structures and enzymic properties of two mutant dihydrofolate reductases ( Escherichia coli ) were studied in order to clarify the functional role of an invariant carboxylic acid (aspartic acid at position 27) at the substrate binding site. One mutation, constructed by oligonucleotide-directed mutagenesis, replaces Asp 27 with asparagine; the other is a primary-site revertant to Ser 27 . The only structural perturbations involve two internally bound water molecules. Both mutants have low but readily measurable activity, which increases rapidly with decreasing p H. The mutant enzymes were also characterized with respect to relative folate: dihydrofolate activities and kinetic deuterium isotope effects. It is concluded that Asp 27 participates in protonation of the substrate but not in electrostatic stabilization of a positively charged, protonated transition state.

Bibliography

Howell, E. E., Villafranca, J. E., Warren, M. S., Oatley, S. J., & Kraut, J. (1986). Functional Role of Aspartic Acid-27 in Dihydrofolate Reductase Revealed by Mutagenesis. Science, 231(4742), 1123â1128.

Authors 5

Elizabeth E. Howell (first)
Jesus E. Villafranca (additional)
Mark S. Warren (additional)
Stuart J. Oatley (additional)
Joseph Kraut (additional)

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Dates

Type	When
Created	18 years, 10 months ago (Oct. 5, 2006, 4:28 p.m.)
Deposited	1 year, 7 months ago (Jan. 14, 2024, 4:20 a.m.)
Indexed	2 months, 2 weeks ago (June 6, 2025, 5:08 a.m.)
Issued	39 years, 5 months ago (March 7, 1986)
Published	39 years, 5 months ago (March 7, 1986)
Published Print	39 years, 5 months ago (March 7, 1986)

Funders 0

None

BibTeX

@article{Howell_1986, title={Functional Role of Aspartic Acid-27 in Dihydrofolate Reductase Revealed by Mutagenesis}, volume={231}, ISSN={1095-9203}, url={http://dx.doi.org/10.1126/science.3511529}, DOI={10.1126/science.3511529}, number={4742}, journal={Science}, publisher={American Association for the Advancement of Science (AAAS)}, author={Howell, Elizabeth E. and Villafranca, Jesus E. and Warren, Mark S. and Oatley, Stuart J. and Kraut, Joseph}, year={1986}, month=mar, pages={1123–1128} }

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