FIGURE 3.
The histone H4 tails are not essential for intra-array compaction of tetranucleosomal arrays. A, shown is a schematic of tetranucleosomal arrays used in this study with octamers possessing or missing histone H4 tails. The presence of the H4 tails in an octamer (T) is represented in schematic form by a clear circle with two tails. The absence of H4 tails (G) is represented by a shaded circle in the schematic. The octamer letter representations are in ascending order with respect to DNA template fragment number, with the exception of the GTTT array, which is in reverse order, i.e. the tailless nucleosome, G, occurs on DNA template fragment four. B, shown is a representative integrated sedimentation coefficient distribution plot of the tetranucleosomal arrays containing octamers with (TTTT) or without (GGGG) H4 tails in the presence and absence of divalent magnesium ion. s20,w is the sedimentation coefficient corrected for water at 20 °C.