6R2E

Crystal structure of the human thymidylate synthase (hTS) interface variant Q62R

Summary for 6R2E

• Entry DOI: 10.2210/pdb6r2e/pdb
• Descriptor: Thymidylate synthase, SULFATE ION, N-[4-({[(6S)-2-amino-5-formyl-4-oxo-3,4,5,6,7,8-hexahydropteridin-6-yl]methyl}amino)benzoyl]-L-glutamic acid, ... (7 entities in total)
• Functional Keywords: human thymidylate synthase, folate pathway, q62r, interface variant, transferase
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 8
• Total formula weight: 304626.38

Authors

Pozzi, C.,Mangani, M. (deposition date: 2019-03-16, release date: 2019-04-10, Last modification date: 2024-01-24)

Primary citation

Pozzi, C.,Lopresti, L.,Santucci, M.,Costi, M.P.,Mangani, S.
Evidence of Destabilization of the Human Thymidylate Synthase (hTS) Dimeric Structure Induced by the Interface Mutation Q62R.
Biomolecules, 9:-, 2019

PubMed Abstract: In human cells, thymidylate synthase (TS) provides the only source of 2'-deoxythymidyne-5'-monophosphate (dTMP), which is required for DNA biosynthesis. Because of its pivotal role, human TS (hTS) represents a validated target for anticancer chemotherapy. Nonetheless, the efficacy of drugs blocking the hTS active site has limitations due to the onset of resistance in cancer cells, requiring the identification of new strategies to effectively inhibit this enzyme. Human TS works as an obligate homodimer, making the inter-subunit interface an attractive targetable area. Here, we report the design and investigation of a new hTS variant, in which Gln62, located at the dimer interface, has been replaced by arginine in order to destabilize the enzyme quaternary assembly. The hTS Q62R variant has been characterized though kinetic assay, thermal denaturation analysis and X-ray crystallography. Our results provide evidence that hTS Q62R has a reduced melting temperature. The effective destabilization of the TS quaternary structure is also confirmed by structural analysis, showing that the introduced mutation induces a slight aperture of the hTS dimer. The generation of hTS variants having a more accessible interface area can facilitate the screening of interface-targeting molecules, providing key information for the rational design of innovative hTS interface inhibitors.

PubMed: 30987202
DOI: 10.3390/biom9040134

Experimental method

X-RAY DIFFRACTION (2.55 Å)