Fig. 4. Paralog interference between Arg80 and Mcm1.

(A) The ratio of functional binding to inhibitory binding determines the extent of competitive interference between Mcm1 and Arg80. (B) Arg80, AncArg80, and AncArg80 mutant with DNA-binding surface changes reverted to ancestral state interfere with α-specific gene expression. α-specific gene expression was quantified by quantitative reverse-transcriptase fluorescence polymerase chain reaction using SAG1 transcript (normalized to URA6 transcript). Endogenous expression is driven by the native ARG80 promoter, and overexpression is driven by the TEF1 promoter. For gene expression experiments, mean and standard error (indicated by error bars) were determined from five replicates.