No information is available with regard to potential nuclear domains involved in RNA polymerase III transcription. In summary, while the nucleus contains domains associated with particular functions, there appears to be a degree of plasticity in this organization since in all likelihood the nuclear contents are dynamic. Cell and Molecular biology. The cells of eukaryotic organisms have a DNA content that is characteristic for each species. Most, if not all, of the DNA is present in chromatin, which is a complex of DNA with an equal weight of basic proteins called histones.
Histones are small proteins which are basic because they have a high content of arginine or lysine.
There are only have histones. The fifth histone, H1, is present only once per 200 base pairs of DNA, and it varies considerbly between species and even within tissues of the same species. Chromatin is formed by a series of repeating units called nucleosomes. Under the EM, nucleosomes can be visualized as beads about 10 nm in diameter. However, in the living cell the nucleosomes touch each other, forming a 10 nm fiber.