DNA binding protein occupancy and DNase I HS analysis in the ANK1 promoter region in K562 cells. (A top) Schematic representation of the ANK1 promoter region showing all 3 alternative promoters. Arrows indicate the location of DNase I HSs. (Bottom) ENCODE data for DNase I HSs (DNase I), CTCF, and RNA Pol II binding. The hg19 coordinates of the expanded 11-kb region are shown below the panel. (B) Southern blot analysis of the 3′ANK1E 3′DNase I HS. Lane 1 contains high-molecular-weight K562 DNA digested with NsiI to reveal a 5.3-kb parent band (PB). Lanes 2 and 3 contain K562 DNA extracted from chromatin treated with a low and a high concentration of DNase I, respectively, and digested with NsiI (N + DNase), which revealed 2 DNase I HSs (HS). Lanes 4 to 10 contain high-molecular-weight DNA digested with NsiI and the indicated second enzyme to identify the boundaries of ANK1E 3′HS1 and 3′HS2. A map of the region showing the restriction sites and the probe used for southern blotting is shown below the data. The dashed lines indicate our best estimate of the boundaries of the HSs shown in lanes 2 and 3.