Differences among chicken erythrocyte histones H1 and H5 in associating with H1-depleted polynucleosomes.

1. Chicken erythrocyte histones H1a, H1b and H5 were associated to H1-depleted polynucleosomes from rat liver and the products were probed by digestion with micrococcal nuclease. 2. The digestion response of complexes with purified H1a or H1b resembled that of native polynucleosomes, while the digestion response of complexes with purified H5 exhibited specific different features--but none of these complexes resembled those with unfractionated histones H1a, H1b and H5. 3. However, after mixing purified histones H1a, H1b and H5 in the proportions (0.15:0.25:0.9) as these occur in erythrocyte nuclei and associating this mixture, the digestion response of the complexes was similar to that of the complexes with unfractionated histones.