EryR mutant frequency in wt and rev3Δ strains transformed with wt or mutant mip1 alleles.

EryR mutant frequency in wt and rev3Δ strains transformed with wt or mutant mip1 alleles was determined as reported in Materials and Methods. “Fold increase mutant mip1/wt MIP1” was obtained by dividing the EryR frequency related to each mip1 allele by the EryR frequency related to MIP1 wt allele. “Fold increase rev3Δ strain/wt strain” was obtained by dividing, for each mip1 allele, the EryR frequency of rev3Δ strain by that of wt strain. * indicates that the fold increase is significantly higher (pMIP1 wt allele.