Crystallization and preliminary X-ray diffraction analysis of human growth and differentiation factor 5 (GDF-5)

Crystals of human growth and differentiation factor 5 are trigonal, belonging to space group P3₁21 or its enantiomer, with one molecule per asymmetric unit and diffract to 2.2 Å resolution. Growth and differentiation factor 5 (GDF-5) belongs to the large TGF-β superfamily of secreted signalling proteins and plays a pivotal role in skeletal development during embryogenesis. The gene for human GDF-5 was cloned, expressed in Escherichia coli and purified to homogeneity. Crystals were obtained that diffracted to 2.2 Å resolution. A native data set was acquired, showing that the crystals belong to a trigonal space group, i.e. P3₁21 or P3₂21, with unit-cell parameters a = b = 97.1, c = 48.3 Å. Initial analysis suggest the presence of only one monomer in the asymmetric unit, resulting in a high solvent content of 72% in the crystal