Work

Deprotonations in the Reaction of Flavin-Dependent Thymidylate Synthase

Year: 2016

Type: article

Abstract: Many microorganisms use flavin-dependent thymidylate synthase (FDTS) to synthesize the essential nucleotide 2'-deoxythymidine 5'-monophosphate (dTMP) from 2'-deoxyuridine 5'-monophosphate (dUMP), 5,10-methylenetetrahydrofolate (CH2THF), and NADPH. FDTSs have a structure that is unrelated to the thymidylate synthase used by humans and a very different mechanism. Here we report nuclear magnetic resonance evidence that FDTS ionizes N3 of dUMP using an active-site arginine. The ionized form of dUMP is largely responsible for the changes in the flavin absorbance spectrum of FDTS upon dUMP binding. dUMP analogues also suggest that the phosphate of dUMP acts as the base that removes the proton from C5 of the dUMP-methylene intermediate in the FDTS-catalyzed reaction. These findings establish additional differences between the mechanisms of FDTS and human thymidylate synthase.

Source: Biochemistry

Authors: Frederick W. Stull, Steffen M. Bernard, Aparna Sapra, Janet L. Smith, Erik R. P. Zuiderweg, Bruce A. Palfey

Institution: University of Michigan

Language: English

Topic: Biochemical and Molecular Research

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: National Science Foundation, National Institutes of Health, National Cancer Institute, National Institute of General Medical Sciences, National Institute of Diabetes and Digestive and Kidney Diseases, Division of Chemistry

Awards: G1380104447, G1468070684, A Novel Mechanism for Pyrimidine Methylation by a Flavin-dependent Enzyme, G2219523378, G222407312, G2362727379, G2363639003, G402281873, G4313171166, G4328287647, G4359711755, G4866076653, G63497290, G7374214904, G9000214759

OpenAlex ID: W2402115195

FWCI: 1.357

Cites: 28

Cited by: 22

Related to: 10