On the binding of histone H1 in chromatin.

Nucleosomal subunits isolated from rabbit thymus nuclei in 0.04 M K2SO4-0.02 M Tris, pH 7.4 were devoid of histone H1, while whole chromatin prepared in the same buffer contained the full complement of histone H1. The question is asked why histone H1 dissociates from the subunits but not from the high molecular weight material. We propose that, at physiological salt concentrations, histone H1 is not bound to linker DNA as depicted in the current models; rather, alternate attachment sites, present only in the polymer, are involved.