Figure 6.

Binding of nuclear factors to the HS7 site D is Zn²⁺-dependent. The site D oligonucleotide probe was incubated with 15 μg of nuclear extracts from Jurkat cells in the absence (lane 1) or in the presence of increasing concentrations (0.5, 1, 1.5 and 2 mM) of 1,10-phenanthroline (lanes 2–13). Increasing amounts of ZnCl₂ (0.4, 0.8, 1 and 1.2 mM) or of MgCl₂ (0.4, 0.8, 1 and 1.2 mM) were added to the binding reactions (lanes 6–9 or lanes 10–13, respectively). The figure shows only the specific retarded bands of interest. The complex D is indicated by an arrow.