By testing variants of the budding yeast phosphate response (PHO) genes, it is shown that the affinity of DNA binding sites that are accessible to a transcription factor determines the threshold for promoter activation, and that the binding sites within nucleosomal regions serve to influence the maximal expression of a gene once the nucleosomes are remodelled. Thus nucleosomes can decouple a promoter's threshold of activation from its dynamic range.
- Felix H. Lam
- David J. Steger
- Erin K. O’Shea
