An RNA fraction in chromatin of L-929 cells associated with DNA.

The DNA of L-929 cell nuclei was examined for the presence of an RNA fraction hybridized to the DNA that could possibly serve a role in gene regulation. A low molecular weight ([unk]4.5S) RNA fraction was observed as an RNA-DNA complex in chromatin preparations subfractionated on a Cs(2)SO(4) density gradient. This RNA does not appear to be covalently attached to the DNA. Neither does it appear to be attached to the DNA via a protein component. The RNA is resistant to ribonuclease H but is slowly attached by ribonuclease A + Tl. A role for, as well as the nature of the attachment of this RNA to DNA is suggested.