Preparation, crystallization and preliminary X-ray diffraction analysis of the DNA-binding domain of the Ets transcription factor in complex with target DNA.

The Ets2 transcription factor is a member of the Ets transcription-factor family. Ets2 plays a role in the malignancy of cancer and in Down's syndrome by regulating the transcription of various genes. The DNA-binding domain of Ets2 (Ets domain; ETSD), which contains residues that are highly conserved among Ets transcription-factor family members, was expressed as a GST-fusion protein. The aggregation of ETSD produced after thrombin cleavage could be prevented by treatment with NDSB-195 (nondetergent sulfobetaine 195). ETSD was crystallized in complex with DNA containing the Ets2 target sequence (GGAA) by the hanging-drop vapour-diffusion method. The best crystals were grown using 25% PEG 3350, 80 mM magnesium acetate, 50 mM sodium cacodylate pH 5.0/5.5 as the reservoir at 293 K. The crystals belonged to space group C2, with unit-cell parameters a = 85.89, b = 95.52, c = 71.89 A, beta = 101.7 degrees and a V(M) value of 3.56 A(3) Da(-1). Diffraction data were collected to a resolution of 3.0 A.