library_construction_protocol: Cells were fixed with 1% formaldehyde for 10 minutes. After quenching and cell lysis, chromatin was sonicated using a Bioruptor Plus sonication (Diagenode). ChIP-seq libraries were prepared using the NEBNext Ultra II DNA Library Prep Kit for Illumina. 10 ng of DNA was used as starting material for input and IP samples. Libraries were amplified using 12 cycles on the thermocycler. Post amplification libraries were size selected at 250-450bp in length using  AMPure XP beads from Beckman Coulter. Libraries were validated using the Qubit High Sensitivity DNA Kit.