Figure 3

Perturbation of the H1 complement of native chromatin. A sample of chromatin (30–35 nucleosomes) containing 30 μg of DNA was mixed with ~8 μg of SAR DNA and ~3 μg of one of the subtypes H1a-e and H1°. This amount of added H1 corresponds to ~0.4 molecules per nucleosome. The insoluble complex of SAR and H1 (p) was separated by centrifugation from chromatin (s) with its H1 complement redefined. Perturbation experiments with H1a, H1c and H1° were analyzed only by SDS gel electrophoresis. Experiments with H1b, H1d and H1e were analyzed by SDS and urea/acetic acid gel electrophoresis. Chromatin inputs analyzed by SDS and AU gel electrophoresis are shown (i). m, mixture of H1 subtypes separated by AU gel electrophoresis. The subtypes H1a-e and H1° are indicated (a-e, 0). CH, core histones.