Figure 4.

Overlapping binding sites in the ICR for CTCF and Zfp57-Trim28-Setdb1 repressor complex explain their antagonistic roles at the ICR. The four CTCF binding sites (inside the blue rectangle) of the ICR are shown with the intertwined consensus sequences defined by Zfp57-Trim28-Setdb1 (underlined in red). The nucleotides that were mutated by point mutations (Engel et al., 2004) that specifically destroy Zfp57-Trim28-Setdb1 consensus sequence are in red. Point mutations that abolish CTCF binding and also destroy Zfp57-Trim28-Setdb1 consensus sites are written in the top line.