Average growth rates for sequence libraries with defined distances between Cbf1 and Met31/32 binding sites. We generated libraries of pooled transformants containing single-copy plasmids with the indicated distances between Cbf1 and Met31/32 binding sites. We induced reporter gene expression by transferring these pooled cultures into media lacking histidine, leucine and methionine, plus the indicated concentration of 3-AT (see Methods for details). The growth rate, expressed in doublings per hour, for each pooled culture was obtained from regular measurements of OD600. The average growth rate and standard error of the mean are plotted for three independent trials.