Crystallization and preliminary structural characterization of the two actin-depolymerization factors of the malaria parasite

The expression, purification and crystallization of Plasmodium actin-depolymerization factors 1 and 2 are described. X-ray diffraction data were collected to 2.0 and 2.1 Å resolution, respectively, and the structures of both proteins in solution were characterized. The malaria parasite Plasmodium depends on its actin-based motor system for motility and host-cell invasion. Actin-depolymerization factors are important regulatory proteins that affect the rate of actin turnover. Plasmodium has two actin-depolymerization factors which seem to have different functions and display low sequence homology to the higher eukaryotic family members. Plasmodium actin-depolymerization factors 1 and 2 have been crystallized. The crystals diffracted X-rays to maximum resolutions of 2.0 and 2.1 Å and belonged to space groups P3₁21 or P3₂21, with unit-cell parameters a = b = 68.8, c = 76.0 Å, and P2₁2₁2, with unit-cell parameters a = 111.6, b = 57.9, c = 40.5 Å, respectively, indicating the presence of one or two molecules per asymmetric unit in both cases