FIG. 5.

Mg²⁺-dependent oligomerization of underacetylated, moderately acetylated, and highly acetylated nucleosomal arrays. Oligomerization was assayed by differential centrifugation as previously described (47, 48). Shown are the percentages of the underacetylated (U), moderately acetylated (M), and highly acetylated (H); samples that remained in the supernatant after exposure to the indicated amounts of MgCl₂ for 10 min at room temperature and centrifugation at 16,000 × g for 10 min in an Eppendorf microcentrifuge. Each data point represents the mean of three to four determinations.