Macromolecular crystallography and what it can contribute to antiparasite drug discovery

An introduction to the special issue on molecular parasitology.

Three-dimensional structures in the design of therapeutics targeting parasitic protozoa: reflections on the past, present and future

A review and historical perspective covering the many different aspects of antiparasitic drug discovery, in particular targeting protists, is presented. The key role of structural studies in the process is highlighted and specific high-profile examples are given.

Towards a molecular understanding of the apicomplexan actin motor: on a road to novel targets for malaria remedies?

In this review, current structural understanding of the apicomplexan glideosome and actin regulation is described.

Solution-state NMR structure of the putative morphogene protein BolA (PFE0790c) from Plasmodium falciparum

Parasitic protozoans of the Plasmodium genus are responsible for malaria, a disease that kills approximately one child every minute in Africa and ∼2000 people per day worldwide. Here, the solution structure of the 84-residue BolA protein PFE0790c from the deadliest Plasmodium species, P. falciparum, is reported.

Structure of a CutA1 divalent-cation tolerance protein from Cryptosporidium parvum, the protozoal parasite responsible for cryptosporidiosis

Cryptosporidium parvum is the primary protozoan parasite from the Cryptosporidium genus responsible for cryptosporidiosis in humans. Here, the 2.0 Å resolution structure of the divalent-cation tolerance protein CutA1 encoded in the genome of C. parvum Iowa II is described.

Structure of Cryptosporidium IMP de­hydrogenase bound to an inhibitor with in vivo antiparasitic activity

Compound P131 displays antiparasitic activity in a mouse model of Cryptosporidium infection, validating IMP dehydrogenase (IMPDH) as a drug target. Here, the structure of the enzyme–substrate–P131 complex is reported at 2.05 Å resolution. The structure is an important step to further refine the design of IMPDH inhibitors.

The structure of tubulin-binding cofactor A from Leishmania major infers a mode of association during the early stages of microtubule assembly

The structure of a tubulin-binding cofactor from L. major is reported and compared with yeast, plant and human orthologues.

Recombinant production, crystallization and crystal structure determination of di­hydroorotate de­hydrogenase from Leishmania (Viannia) braziliensis

The crystal structure of L. (V.) braziliensis dihydroorotate dehydrogenase, a potential target for drug development against cutaneous leishmaniasis, is reported.

The X-ray structure of Plasmodium falciparum di­hydroorotate de­hydrogenase bound to a potent and selective N-phenylbenzamide inhibitor reveals novel binding-site interactions

The X-ray structure of the antimalarial drug target dihydroorotate dehydrogenase bound to a potent and selective benzamide-based inhibitor shows novel binding-site interactions.

Structure of uridine diphosphate N-acetylglucosamine pyro­phosphorylase from Entamoeba histolytica

Uridine diphosphate N-acetylglucosamine pyrophosphorylase (UAP) synthesizes UDP-GlcNAc. E. histolytica UAP appears to lack the N-terminal extension of UAP from other parasites that is partially involved in allosteric regulation by small-molecule inhibitors.

Structures of aspartate aminotransferases from Trypanosoma brucei, Leishmania major and Giardia lamblia

Structures of aspartate aminotransferases from eukaryotic pathogens were solved in complex with pyridoxal phosphate. The four structures show either the open or the closed conformation of the enzyme.

Structures of a histidine triad family protein from Entamoeba histolytica bound to sulfate, AMP and GMP

Structures of the histidine triad family protein from E. histolytica were solved in complex with sulfate, AMP or GMP. The three structures show very similar nucleotide poses, with the sulfate occupying the same space as the α-phosphate of the nucleotides.

Production, purification and crystallization of a trans-sialidase from Trypanosoma vivax

The production, purification and crystallization of a recently identified trans-sialidase from T. vivax is described. The purified enzyme is active and produces diffraction-quality crystals using the sitting-drop vapour-diffusion method. The crystals belonged to space group P2₁2₁2₁ and diffracted to 2.5 Å resolution.

Identification and structure solution of fragment hits against kinetoplastid N-myristoyltransferase

N-Myristoyltransferase (NMT) has been shown to be an attractive target for the development of novel therapeutic agents for the treatment of human African trypanosomiasis. A fragment library has been screened using NMR spectroscopy and the binding mode of the hits was confirmed by X-ray crystallography using L. major NMT as a structural surrogate.

Structure of an ADP-ribosylation factor, ARF1, from Entamoeba histolytica bound to Mg²⁺–GDP

ADP-ribosylation factors (ARFs) are highly conserved proteins present in all eukarya. The structure of ARF1 from E. histolytica is described and compared with orthologs from other species.

Structure of Plasmodium falciparum orotate phosphoribosyltransferase with autologous inhibitory protein–protein interactions

P. falciparum orotate phosphoribosyltransferase, a potential target for antimalarial drugs and a conduit for prodrugs, crystallized as a structure with eight molecules per asymmetric unit that included some unique parasite-specific auto-inhibitory interactions between catalytic dimers.

Structures of prostaglandin F synthase from the protozoa Leishmania major and Trypanosoma cruzi with NADP

High-resolution crystal structures of the prostaglandin F synthase enzymes from the protazoa T. cruzi and L. major were solved with and without the cofactor NADP.

Iron superoxide dismutases in eukaryotic pathogens: new insights from Apicomplexa and Trypanosoma structures

Superoxide dismutases (SODs) catalyze the conversion of superoxide to molecular oxygen, thus protecting organisms against toxic radicals. Iron-dependent SODs from T. cruzi, L. major and B. bovis exist as multiple isoforms with distinct structural features.