Fig. 7. ABD-B binds to the dap regulatory region in vitro. EMSA was performed after incubating radiolabeled double stranded oligonucleotides with either buffer (none) or reticulocyte lysate that contained ABD-B protein (ABD-B) or which did not contain ABD-B protein (mock). ABD-B binds to the wild-type sequence present in the A8 block of the dap gene of Drosophila virilis (Dv-wt) and Drosophila melanogaster (Dm-wt). However, ABD-B does not bind when the sequences corresponding to the ABD-B core binding motif are mutated within this region (Dm-mut). The specificity of the binding to Dm-wt was further confirmed by experiments in which a ten- or one hundredfold excess of unlabeled oligonucleotides were added to the binding reaction as competitors (comp). Dm-wt but not Dm-mut acted as a competitor.