Crystallographic characterization of the DIX domain of the Wnt signalling positive regulator Ccd1

Coiled-coil DIX1 (Ccd1) is a positive regulator that activates the canonical Wnt signalling pathway by inhibiting the degradation of the key signal transducer [beta]-­catenin. The C-terminal DIX domain of Ccd1 plays an important role in the regulation of signal transduction through homo-oligomerization and protein complex formation with other DIX domain-containing proteins, i.e. axin and dishevelled proteins. Here, the expression, purification, crystallization and X-ray data collection of the Ccd1 DIX domain are reported. The crystals of the Ccd1 DIX domain belonged to space group P2₁2₁2₁, with unit-cell parameters a = 72.9, b = 75.7, c = 125.6 Å. An X-ray diffraction data set was collected at 3.0 Å resolution.