Crystal structures of the closed form of Mycobacterium tuberculosis dihydrofolate reductase in complex with dihydrofolate and antifolates

Author(s)

Ribeiro, Joao Augusto ; Chavez-Pacheco, Sair Maximo ; de Oliveira, Gabriel Stephani ; Silva, Catharina dos Santos ; Pimenta Giudice, Joao Henrique ; Libreros-Zuniga, Gerardo Andres ; Bertacine Dias, Marcio Vinicius

• Document type: Journal article
• Source: ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY; v. 75, p. 12-pg., 2019-07-01.

Abstract

Tuberculosis is a disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious pathogen, with a high prevalence in developing countries in Africa and Asia. There still is a need for the development or repurposing of novel therapies to combat this disease owing to the long-term nature of current therapies and because of the number of reported resistant strains. Here, structures of dihydrofolate reductase from M.tuberculosis (MtDHFR), which is a key target of the folate pathway, are reported in complex with four antifolates, pyrimethamine, cycloguanil, diaverdine and pemetrexed, and its substrate dihydrofolate in order to understand their binding modes. The structures of all of these complexes were obtained in the closed-conformation state of the enzyme and a fine structural analysis indicated motion in key regions of the substrate-binding site and different binding modes of the ligands. In addition, the affinities, through K-d measurement, of diaverdine and methotrexate have been determined; MtDHFR has a lower affinity (highest K-d) for diaverdine than pyrimethamine and trimethoprim, and a very high affinity for methotrexate, as expected. The structural comparisons and analysis described in this work provide new information about the plasticity of MtDHFR and the binding effects of different antifolates. (AU)

• FAPESP's process: 13/15906-5 - Fragment based drug discovery (FBDD) applied to two enzymes of folate biosynthetic pathway from Mycobacterium tuberculosis
• Grantee: João Augusto Ribeiro
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/00351-1 - Applied structural biology involved in the biosynthesis of natural products: biotechnolgical aplications and study of unusual molecular reactions
• Grantee: Marcio Vinicius Bertacine Dias
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/09188-8 - Biosynthesis of polyether and aminoglycoside antibiotics: structural investigation of unusual enzymes or with synthetic biology applicability
• Grantee: Marcio Vinicius Bertacine Dias
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/24486-2 - Structural basis of sensibility of Mycobacterium tuberculosis and M. leprae dihydropteroate synthase to the sulfonamide drugs
• Grantee: João Henrique Pimenta Giudice
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 16/18721-4 - Structural basis of the elongation and cell division control in Mycobacterium tuberculosis and identification of new drug hits based in fragment trials
• Grantee: Catharina dos Santos Silva
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)