Saturation mutagenesis of yeast FCY1 promoter

A yeast mutant library containing all single mutations (substitutions, insertions and deletions) of the FCY1 promoter was assayed. Fitness in 5-FC [12 uM] was first measured using bulk competition for 20 population doublings, with intermediate dilution steps (samples collected at T0, T1, T2 and T3). Second, a sort-seq approach was used to measure the corresponding expression level for each variant, from a another version of the mutant pool where FCY1 was replaced with a fluorescent marker.