library_construction_protocol: ChIP-seq: Chromatin fragments were purified using MiniElute columns (Qiagen), ChIP-seq libraries were prepared using NEBNext kit (New England Biolabs) and sequenced with HiSeq2000 at EMBL GeneCore (Heidelberg, Germany). RNA-seq: Total RNA was extracted from four biological replicates using TriPure isolation reagent (Roche) and treated with DNAse. RNA-seq libraries were prepared using NEBNext Poly(A) mRNA Magnetic isolation module (New England Biolabs) and sequenced with Illumina HiSeq2000 at EMBL GeneCore (Heidelberg, Germany).