Structure of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase–dihydropteroate synthase from Plasmodium vivax sheds light on drug resistance

DOI: 10.1074/jbc.RA118.004558

Authors: Manickam Yogavel (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Joanne E. Nettleship (Wellcome Centre for Human Genetics, University of Oxford; Oxford Protein Production Facility) , Akansha Sharma (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Karl Harlos (Wellcome Trust Centre for Human Genetics, University of Oxford) , Abhishek Jamwal (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Rini Chaturvedi (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Manmohan Sharma (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Vitul Jain (Wellcome Centre for Human Genetics, University of Oxford) , Jyoti Chhibber-Goel (International Centre for Genetic Engineering and Biotechnology (ICGEB)) , Amit Sharma (International Centre for Genetic Engineering and Biotechnology (ICGEB))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Biological Chemistry

State: Published (Approved)
Published: August 2018
Diamond Proposal Number(s): 14744

Abstract: The genomes of the malaria-causing Plasmodium parasites encode a protein fused of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) and dihydropteroate synthase (DHPS) domains that catalyze sequential reactions in the folate biosynthetic pathway. Whereas higher organisms derive folate from their diet and lack the enzymes for its synthesis, most eubacteria and a number of lower eukaryotes including malaria parasites synthesize tetrahydrofolate via DHPS. Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) HPPK-DHPSs are currently targets of drugs like sulfadoxine (SDX). The SDX effectiveness as an antimalarial drug is increasingly diminished by rise and spread of drug resistance mutations. Here, we present the crystal structure of PvHPPK-DHPS in complex with four substrates/analogs, revealing the bifunctional PvHPPK-DHPS architecture in an unprecedented state of enzymatic activation. SDX’s effect on HPPK-DHPS is due to 4-amino benzoic acid (pABA) mimicry, and the PvHPPK-DHPS structure sheds light on the SDX-binding cavity as well as on mutations that effect SDX potency. We mapped five dominant drug resistance mutations in PvHPPK-DHPS: S382A, A383G, K512E/D, A553G, and V585A, most of which occur individually or in clusters proximal to the pABA-binding site. We found that these resistance mutations subtly alter the intricate enzyme/pABA/SDX interactions such that DHPS affinity for pABA is diminished only moderately, but its affinity for SDX is changed substantially. In conclusion, the PvHPPK-DHPS structure rationalizes and unravels the structural bases for SDX resistance mutations and highlights architectural features in HPPK-DHPSs from malaria parasites that can form the basis for developing next-generation anti-folate agents to combat malaria parasites.

Journal Keywords: dihydropteroate synthase; sulfadoxine; Plasmodium vivax; p-aminobenzoic acid; HPPK-DHPS; drug resistance; infectious disease; malaria; plasmodium; crystal structure

Diamond Keywords: Malaria

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Instruments: I03-Macromolecular Crystallography

Added On: 23/08/2018 09:11

Documents:
jbc.RA118.004558.full.pdf

Discipline Tags:

Infectious Diseases Disease in the Developing World Health & Wellbeing Biochemistry Chemistry Structural biology Drug Discovery Life Sciences & Biotech Parasitology

Technical Tags:

Diffraction Macromolecular Crystallography (MX)