Transcription factor; regulates multidrug resistance and the oxidative stress response; forms a heterodimer with Pdr1p; contains a Zn(II)2Cys6 zinc finger domain that interacts with a pleiotropic drug resistance element in vitro; negative regulator of autophagy, modulating the transcription of genes involved in NADPH production and the pentose phosphate pathway; Stb5p expression is reduced during nitrogen starvation and autophagy induction, while STB5 mRNA levels are significantly increased