ChIP was performed using the methods of T. I. Lee, S. E. Johnstone, R. A. Young, Chromatin immunoprecipitation and microarray-based analysis of protein location. Nat Protoc. 1, 729–748 (2006). Libraries were prepared using the NEBNext Multiplex Oligos for Illumina kit (NEB) and run on an Illumina Hi-Seq2000.