Contacts of the globular domain of histone H5 and core histones with DNA in a "chromatosome".

The globular domain of histone H5 is found to asymmetrically associate with a nucleosome core including the Xenopus borealis somatic 5S RNA gene. Histones H2A and H2B are required for association of histone H5. Strong crosslinking of the globular domain of histone H5 to the 5S DNA in the nucleosome occurs at a single site to one side of the dyad axis. This site is also in contact with the core histones, and the interactions of the core histones with 5S DNA change as a result of association of the globular domain of histone H5. We discuss evidence for an allosteric change in core histone-5S DNA interactions following the association of the linker histone in the nucleosome. IMAGES: