Crystal structure of Plasmodium vivax macrophage migration inhibitory factor.

Plasmodium vivax is a major cause of malaria globally and has recently been transmitted locally in the USA. P. vivax produces homologs of host proteins, including cytokines such as macrophage migration inhibitory factor (MIF). MIF regulates both adaptive and innate immune responses and contributes to the pathogenesis of parasitic infections, including malaria. Plasma concentrations of P. vivax MIF (PvMIF) correlate with the severity of P. vivax malaria. Plasmodium spp. MIFs have been recognized as candidate malaria vaccines. PvMIF, like other protozoan MIFs, binds to host CD74 and can suppress host MIF-CD74 signaling. The production, crystallization and 1.8 Å resolution structure of PvMIF (PDB entry 9b0m, pdb_00009b0m) are reported. PvMIF crystallized in space group P63 with a single molecule in the asymmetric unit. The biological unit of PvMIF is the prototypical MIF trimer.