Structure of the Y94F mutant of Escherichia coli thymidylate synthase
- Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721 (United States)
- Department of Biology, Drake University, Des Moines, IA 50311 (United States)
- Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509 (United States)
Mutation of Tyr94 of E. coli thymidylate synthase to phenylalanine leads to a protein with k{sub cat} reduced by a factor of 400. The Y94F structure is essentially identical to the wild-type structure, which is consistent with a catalytic role for the phenolic OH. Tyr94 of Escherichia coli thymidylate synthase is thought to be involved, either directly or by activation of a water molecule, in the abstraction of a proton from C5 of the 2′-deoxyuridine 5′-monophosphate (dUMP) substrate. Mutation of Tyr94 leads to a 400-fold loss in catalytic activity. The structure of the Y94F mutant has been determined in the native state and as a ternary complex with thymidine 5′-monophosphate (dTMP) and 10-propargyl 5,8-dideazafolate (PDDF). There are no structural changes ascribable to the mutation other than loss of a water molecule hydrogen bonded to the tyrosine OH, which is consistent with a catalytic role for the phenolic OH.
- OSTI ID:
- 22356436
- Journal Information:
- Acta Crystallographica. Section F, Journal Name: Acta Crystallographica. Section F Journal Issue: Pt 9 Vol. 62; ISSN ACSFCL; ISSN 1744-3091
- Country of Publication:
- United Kingdom
- Language:
- English
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