Binds to the DNA sequence mediating pheromone induction (called the pheromone response element = PRE) which is found in the upstream control region of several a-, alpha- and haploid-specific genes. Involved in mating of haploids and in pseudohyphae formation in diploids. Interacts with mating-type protein ALPHA1. The DNA-binding domain seems to be involved in the suppression of pseudohyphae formation under nitrogen-rich conditions and in haploids. This region is also involved in the regulation of budding pattern of haploids. Phosphorylated by the STE7, STE11 and STE20 kinases. Present with 1920 molecules/cell in log phase SD medium. Belongs to the STE12 transcription factor family.