Crystals of ternary protein-DNA complexes composed of DNA-binding domains of c-Myb or v-Myb, C/EBP alpha or C/EBP beta and tom-1A promoter fragment

c-Myb and the C/EBP family are transcriptional regulatory factors that act in concert to regulate the expression of myeloid-specific genes. v-Myb enco ded by avian myeloblastosis virus (AMV) is a mutated form of c-Myb that con tains point mutations which disrupt the cooperation with C/EBPs. To underst and the mechanism of the transcriptional synergy between c-Myb and C/EBPs a nd the effect of the v-Myb mutations on that synergy, knowledge based on th eir three-dimensional structures is essential. Crystals of ternary complexe s, in which various combinations of the DNA-binding domains of c-Myb or v-M yb and C/EBP alpha or C/EBP beta are bound to a DNA fragment from tom-1A pr omoter, were obtained by the vapour-diffusion method. Complete diffraction data sets were obtained from each native crystal and two types of iodine-de rivative crystals. A three-wavelength MAD data set was also obtained from a bromine-derivative crystal.