Fig. 1.
Relationship between linker length and chromatin fiber diameter. (A) Gallery of side views of negatively stained fibers of 72 × 177-bp (177), 52 × 187-bp (187), 61 × 197-bp (197), 47 × 207-bp (207), 55 × 217-bp (217), 66 × 227-bp (227), and 56 × 237-bp (237) 601 nucleosome arrays reconstituted with saturating concentrations of histone octamer and linker histone H5 and folded in 1.6 mM MgCl2. Images show both individual fibers and longer aggregates formed through the end-to-end stacking of folded arrays as described for native chromatin containing linker histone (48, 53). (B) Images of the 72 × 177-bp fibers captured in the frozen hydrated state by using electron cryo-microscopy. (Scale bar: 100 nm.)