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.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)