Transcription factor binding on designed libraries measured by CCRAs

We measured transcription factor binding and expression of designed syththetic promoter libraries using Calling Cards Reporter Arrays (CCRAs). In this study, we showed that CCRAs is able to make quantatitive measurements for many TFs in yeast. We then demonstrate the quantitative analysis of cooperative interactions by measuring Cbf1p binding at synthetic promoters with multiple sites. Finally, we characterize the binding and expression of a group of TFs, Tye7p, Gcr1p, and Gcr2p, that act together as a “TF collective”, an important but poorly characterized model of TF cooperativity. We demonstrate that Tye7p often binds promoters without its recognition site because it is recruited by other collective members, whereas these other members require their recognition sites, suggesting a hierarchy where these factors recruit Tye7p but not vice versa. Our experiments establish CCRA as a useful tool for quantitative investigations into TF binding and function. Overall design: Using Calling Cards on a arrary of designed promoter sequences