Lysates were clarified from sonicated nuclei and protein-DNA complexes were isolated with antibody. ChIP-seq libraries were prepared using Truseq ChIP-Seq Sample Prep Kit (Illumina, IP-202-1012) following the manufacturer's protocol with some modifications. Briefly, 10 ng of ChIP enriched DNA or control DNA were end repaired using T4 DNA polymerase, Klenow DNA polymerase and T4 Poly Nucleotide Kinase . A single ‘A’ nucleotide was added to the 3’ ends of the blunt DNA fragments with a Klenow fragment (3' to 5'exo minus). The ends of the DNA fragments were ligated to double stranded adapters using T4 DNA ligase. The ligated products were enriched by PCR (30 sec at 98°C [10 sec at 98°C, 30 sec at 65°C, 30 sec at 72°C] x 14 cycles; 5 min at 72°C), then size selected and purified using Agencourt AMPure XP beads (#A63881, Beckman). Prior to analyses DNA libraries were checked for quality and quantified using a 2100 Bioanalyzer (Agilent). The libraries were loaded in the flowcell at 7pM concentration and clusters were generated using the Cbot (Illumina, SY-301-2002 ) and sequenced on the Illumina Genome Hiseq2500 as single-end 50 base reads following Illumina’s instructions