LCR hypersensitive sites act synergistically in recruiting Sp1 pointer. Recruitment of Sp1 pointer ABCZD to target plasmids containing various combinations of the 5′HSs of the LCR (lanes: 1, p306; 2, pPN86; 3, p382; 4, p381; 5, p558; 6, p560; 7, p561; 8, p269) shown below was analyzed with PIN*POINT. Primer extension on the noncoding strand is shown. Positions of the UA region, the tandem CACCC boxes (solid circle), the overlapping GATA-1/CAAT box (solid rectangle), and the TATA box (T) of the β-globin promoter are also shown. Primer extension was performed as before (Fig. 2b). The site of the cleavage detectable in lanes 5–8 is approximately 10 bp upstream of the distal CACCC box (see Fig. 2b, band 1). The positions of the distal CACCC box and the TATA box are shown with the size markers.