Nucleosome arrangement in α-satellite chromatin of african green monkey cells

By analyzing the accessibility of restriction endonuclease sites in African green monkey α-satellite chromatin, we demonstrate the absence of a unique phase relationship between nucleosomes and α-satellite DNA. The data indicate a minimum of three different positions for nucleosome cores relative to the α-satellite sequence ana suggest a random distribution in at least some regions. In addition, while we confirm published reports that staphylococcal nuclease cuts the α-satellite sequence in chroniatin at a highly preferred site, two-dimen sional gel electrophoresis of nuclear digests demonstrates that this site is preferentially cut by staphylococcal nuclease even when it is within the nucleosome core. These data indicate that staphylococcal nuclease is not useful for determining nucleosome positions on α-satellite DNA, and perhaps on other specific DNA sequences as well.