Recombinant Production, Purification and Crystallization of the Toxoplasma Gondii Coronin WD40 Domain

Toxoplasma gondii is one of the most widely spread parasitic organisms in the world. Together with other apicomplexan parasites, it utilizes a special actin-myosin motor for its cellular movement, called gliding motility. This actin-based process is regulated by a small set of actin-binding proteins, which in Apicomplexa comprises only 10-15 proteins, compared with >150 in higher eukaryotes. Coronin is a highly conserved regulator of the actin cytoskeleton, but its functions, especially in parasites, have remained enigmatic. Coronins consist of an N-terminal actin-binding $\beta$-propeller WD40 domain, followed by a conserved region, and a C-terminal coiled-coil domain implicated in oligomerization. Here, the WD40 domain and the conserved region of coronin from $\mathit{T}$. $\mathit{gondii}$ were produced recombinantly and crystallized. A single-wavelength diffraction data set was collected to a resolution of 1.65 Å. The crystal belonged to the orthorhombic space group $C222_{1}$, with unit-cell parameters $\mathit{a}$ = 55.13, $\mathit{b}$ = 82.51, $\mathit{c}$ = 156.98 Å