Fig. 4. In vitro binding of DimB to R2. Full-length DimB:HIS fusion protein was used in band shift assays. The probe is R2 and the unlabelled competitors are R1, R2, a fragment (gatcCTTTTAATGTTAGAAATAGGAGATGAAA) from the promoter of the ecmB gene and a fragment (gatcAAATCCAAACAAAAAAAAAAAATTGATTGTTTTTT) from the promoter of the discoidin 1 gene. The ecmB oligonucleotide is the activator, that binds to DdSTATa and to an unidentified protein by virtue of repeated GAAA tracts (Ceccarelli et al., 2000). The discoidin 1 promoter fragment, the TTG element, is an activator of early gene expression but the binding protein is not known (Vauti et al., 1990).