Preferential binding of H1e histone to GC-rich DNA.

We have investigated the binding of a pure H1 histone, the mouse variant H1e, to a 214 bp fragment of DNA from pBR322. Binding was monitored by observing the effects of the protein on melting of the DNA and by a gel-mobility-shift assay. We found, using this highly purified system, that H1e protein binds preferentially and cooperatively to the GC-rich region of the DNA. A chemically synthesized peptide containing 25 residues, corresponding to a region of the carboxyl-terminal domain of H1e, shows the same sequence preference but does not exhibit cooperativity.