teiser relies on calculating mutual information values between whole - genome measurements and millions of predefined structural motifs . the decoy / scrambled experiments and sirna knock - downs were performed using lipofectamin 2000 reagent ( invitrogen ) . for hybridizations , we used human 444k whole - genome human arrays ( agilent ) . isolation and identification of rna - binding proteins were based on previously published protocols . full methods and any associated references are available in the online version of the paper at www.nature.com/nature .