(A) Motif-wise combinatorial mutations within the core promoter: motif strength and motif position are changed individually. From top to bottom: knockout of motifs (individual or pairwise knockout of motifs, and knockout of all motifs); replacing the original motif with its computationally (XXmotif) derived sequences with different PWM scores (consensus with the highest score), or insertion of the consensus into the motif-less promoter sequences; point mutation of motifs; substitution with functionally or positionally equivalent motifs from other architectures; shift of motif positions; sequence context exchange between different core promoters. The Mec2 motif composition is shown here as an example. 