Preferential and cooperative binding of histone I to chromosomal mammalian DNA

There is a strong preferential binding of histone I to lymphocyte DNA as compared to Escherichia coli DNA when large DNA fragments (2 times 10-6 daltons) are used. The binding of histone I to lymphocyte DNA and to E. coli DNA is cooperative. The distribution of preferential binding sites has been investigated on fragmented DNA. Most of the 2 times 10-6 dalton fragments were found to have at least one preferential histone I binding site, whereas most of the 2 times 10-5 dalton fragments have none.