Cells were fixed with 2mM DSG (Theromo Scientific) for 30min at room temperature followed by cross-linking with 1% formaldehyde (methanol free) for 15 min at room temperature, and cross-linking was stopped by the addition of 0.125 M glycine. Cells were lysed in 1% SDS, 10 mM EDTA, 50 mM Tris-HCl, pH 8.0, and protease inhibitors. Lysates were sonicated in a Covaris ultrasonicator to achieve a mean DNA fragment size of 500 bp. Samples were diluted 1:10 in modified RIPA buffer (1% Triton X-100, 0.1% deoxycholate, 90 mM NaCl, 10 mM Tris-HCl, pH 8.0, and protease inhibitors) and incubated rotating with antibody for a minimum of 12 h at 4 °C. Protein A Dynabeads (Life Technologies) were used to bind the antibody and associated chromatin. After washing and elution from the beads, samples were reverse cross-linked overnight and purified with MinElute PCR purification kit (Qiagen). Sequencing libraries were prepared from eluted DNA using Rubicon ThruPLEX DNA-seq kit.