Cells were cross-linked with 1% formaldehyde for 10 minutes at room temperature. Glycine was added at a final concentration of 125 mM to quench the formaldehyde. Cells were then washed twice with PBS and harvested in SDS buffer (50 mM Tris at pH 8.1, 0.5% SDS, 100 mM NaCl, 5 mM EDTA). Cells were pelleted down, resuspended in Triton-X IP buffer (100 mM Tris at pH 8.6, 0.3% SDS, 1.7% Triton X-100, and 5 mM EDTA) and the chromatin was sonicated to get the DNA fragments of <1000 bp with average DNA fragment size of 300 bp. 500 μg chromatin was used to perform chromatin immunoprecipitation (ChIP) 10 ng of ChIP DNA was used to make library using NEBNext Ultra DNA library kit for illumine (E7370; New England Biolabs) according to supplier's instructions and the libraries were sequenced using Illumina HiSeq2500 sequencer.