Abstract
Transcription factors (TFs) regulate gene expression by binding to cis-regulatory regions that contain their specific binding motifs. In budding yeast, intrinsically disordered regions (IDRs) have emerged as key effectors of genome preferences; however, whether this principle holds in the complex mammalian genomes remains unclear. Here, we profile the binding of three nuclear steroid receptors (SRs) containing long disordered N-terminal domains (NTDs), confirming that the NTDs direct SR binding across genomes. Motif enrichment, coupled with footprint analysis, reveals that SR mutants lacking their NTDs favor binding in proximity to the AP-1 motif, whereas the NTD permits binding at the canonical SR motif also when distant from AP-1 sites. Furthermore, profiling SRs and their mutants in budding yeast confirms that the NTD can direct genome targeting also in the absence of its mammalian-specific interactors. Our results provide new insights into the specificity of SR target selection, opening new avenues for the potential modulation of their activities.