Structural comparison of enterococcus faecalis and human thymidylate synthase complexes with the substrate dUMP and its analogue FdUMP provides hints about enzyme conformational variabilities

DOI: 10.3390/molecules24071257

Authors: Cecilia Pozzi (University of Siena) , Stefania Ferrari (University of Modena and Reggio Emilia) , Rosaria Luciani (University of Modena and Reggio Emilia) , Giusy Tassone (University of Siena) , Maria Costi (University of Modena and Reggio Emilia) , Stefano Mangani (University of Siena)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Molecules , VOL 24

State: Published (Approved)
Published: March 2019
Diamond Proposal Number(s): 1358

Abstract: Thymidylate synthase (TS) is an enzyme of paramount importance as it provides the only de novo source of deoxy-thymidine monophosphate (dTMP). dTMP, essential for DNA synthesis, is produced by the TS-catalyzed reductive methylation of 2′-deoxyuridine-5′-monophosphate (dUMP) using N5,N10-methylenetetrahydrofolate (mTHF) as a cofactor. TS is ubiquitous and a validated drug target. TS enzymes from different organisms differ in sequence and structure, but are all obligate homodimers. The structural and mechanistic differences between the human and bacterial enzymes are exploitable to obtain selective inhibitors of bacterial TSs that can enrich the currently available therapeutic tools against bacterial infections. Enterococcus faecalis is a pathogen fully dependent on TS for dTMP synthesis. In this study, we present four new crystal structures of Enterococcus faecalis and human TSs in complex with either the substrate dUMP or the inhibitor FdUMP. The results provide new clues about the half-site reactivity of Enterococcus faecalis TS and the mechanisms underlying the conformational changes occurring in the two enzymes. We also identify relevant differences in cofactor and inhibitor binding between Enterococcus faecalis and human TS that can guide the design of selective inhibitors against bacterial TSs.

Journal Keywords: thymidylate synthase; Enterococcus faecalis; half-site reactivity; x-ray structure; selectivity

Diamond Keywords: Bacteria

Subject Areas: Biology and Bio-materials, Medicine


Instruments: I03-Macromolecular Crystallography , I04-1-Macromolecular Crystallography (fixed wavelength) , I24-Microfocus Macromolecular Crystallography

Other Facilities: P14 at PETRA III

Added On: 10/04/2019 11:06

Documents:
molecules-24-01257.pdf

Discipline Tags:

Pathogens Infectious Diseases Health & Wellbeing Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)