Lysates were clarifed from sonicated nuclei and histone-DNA complexes were isolated with antibody. Libraries were constructed using the standard protocol for the NEBNext Ultra II DNA Library Prep kit from Illumina (Part#E6240). Briefly, DNA was end-repaired and the blunt, phosphorylated ends were then treated with Klenow fragment (3' to 5' exo minus) and dATP to yield a protruding 3- 'A' base for ligation of Illumina's adaptors which have a single 'T' base overhang at the 3' end. AMPure XP beads were used for size selection of the dA-tailed DNA and then the DNA was PCR amplified with Illumina primers for 15 cycles and library fragments of ~275bp were purified using the AMPure XP beads. Libraries were sequenced on the Illumina HiSeq2000 according to the manufacturer's instructions. Paired-end sequencing was not used.