Chromatin Immunoprecipitation (ChIP) was performed as described previously (Kim et al., 2009; Das et al., 2014). For bioChIP reactions, streptavidin beads (Dynabeads MyOne Streptavidin T1- Invitrogen) were used for the precipitation of chromatin, and 2% SDS was applied for first washing step. All other steps were same as conventional ChIP protocol. 2-10 ng of purified ChIP DNA was used to prepare sequencing libraries, using NEBNext ChIP-seq Library Prep Master Mix Set for Illumina (NEB) and NEBNext Ultra DNA Library Prep Kit for Illumina (NEB) according to the manufacturer's instructions.