Non-cooperative mechanism for bounded and ultrasensitive chromatin remodeling

•A non-cooperative model features highly ultrasensitive DNA density transitions.•Based on DNA percolation effects and multiple acetylation sites per nucleosome.•Bounded low density chromatin regions without uncontrolled DNA unpacking.•Use of DNA graphs allows to specify different spatial chromatin structures.•Transcription factor binding sites determine which regions of DNA to unpack.•Model consistent with significant experimental evidence in the literature.