Chromatin was fragmented by a combination of sonication and MNase digestion. Chromatin immunoprecipitation was performed using anti-FLAG M2 bound to Protein G Dynabeads. Beads were washed in low salt buffer, high salt buffer, LiCl buffer and TE buffer. Protein/DNA complexes were eluted, reverse-crosslinked overnight at 65°C and treated with RNase A and proteinase K. ChIP DNA was purified using Qiaquick PCR Purification kit (Qiagen). Approximately 150 ng DNA was used for library construction according to Illumina’s TruSeq protocol. Libraries were size-selected (200–500 bp) by agarose gel purification, assessed for quality using the High Sensitivity DNA Bioanalyzer kit (Agilent). Libraries were sequenced on the Illumina HiSeq 2000 platform as 50 bp single-end reads