DNA-BINDING INDUCED CONFORMATIONAL CHANGE OF THE YEAST TRANSCRIPTIONAL ACTIVATOR PRTF

Our studies using proteases to probe protein structure establish that binding to the upstream activating sequences (UASs) of two different yeast a-specific genes induces a conformational change in the pheromone/receptor transcription factor (PRTF), which is not observed upon binding to the UASs of either of two α-specific genes. We propose that this selective structural alteration exposes an activation region of PRTF when it binds a-specific genes, switching these genes on. The transcriptional activator MATα1 may activate α-specific genes by binding to the PRTF-α-specific UAS complex and unmasking the otherwise hidden activation surface of PRTF. We also show that the N-terminal third of PRTF is sufficient for specific DNA binding, while the middle third of the protein interacts with MATα1. © 1990.