On the overlap of transcription factor binding and regulatory targets: functional and regulatory coherence of top-bound targets is masked by weakly bound ones

A recent study that systematically mapped genomic bindings and regulatory effects of transcription factors (TFs) reported a surprisingly low overlap between TF binding and regulatory targets in Saccharomyces cerevisiae1. Our analysis suggests that this conclusion depends on the permissive definition of binding targets, which includes a large fraction of weakly bound sites.