The Organization of Proteins in Polyoma and Cellular Chromatin
This extract was created in the absence of an abstract.
Excerpt
In 1973 Hewish and Burgoyne reported that the DNA of rat liver cells was digestible by a calcium-dependent endonuclease into 200 base-pair fragments, or a multiple of this size. In mouse liver nuclei, essentially all of the DNA is degradable to the 200 or 400 base-pair fragments. Presumably a combination of histones protects the 200 base-pair segment of the DNA from nucleolytic attack. The 55S nucleoprotein complexes of polyoma extracted from the nuclei of infected 3T6 cells and from virus particles are also digested by the calcium-dependent endonuclease into 200 base-pair fragments; in contrast, free polyoma DNA is rapidly degraded into small polynucleotides. These data suggest that the proteins of the viral nucleoprotein complex are in an orderly arrangement similar to that of the host chromatin.
Endonuclease Digestion of Mouse Liver Nuclei
Nuclei of rat liver contain an endonuclease activated by calcium, as shown by Hewish and Burgoyne (1973). Autodigestion...
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↵* Present address: Department of Medical Biochemistry, University of Calgary, Calgary, Alberta, Canada.
