Structure of the Pho85-Pho80 CDK-Cyclin Complex of the Phosphate-Responsive Signal Transduction PathwayHuang, K., Ferrin-O'Connell, I., Zhang, W., Leonard, G.A., O'Shea, E.K., Quiocho, F.A.
(2007) Mol Cell 28: 614-623
- PubMed: 18042456
- DOI: https://doi.org/10.1016/j.molcel.2007.09.013
- Primary Citation of Related Structures:
- PubMed Abstract:
The ability to sense and respond appropriately to environmental changes is a primary requirement of all living organisms. In response to phosphate limitation, Saccharomyces cerevisiae induces transcription of a set of genes involved in the regulation of phosphate acquisition from the ambient environment. A signal transduction pathway (the PHO pathway) mediates this response, with Pho85-Pho80 playing a vital role. Here we report the X-ray structure of Pho85-Pho80, a prototypic structure of a CDK-cyclin complex functioning in transcriptional regulation in response to environmental changes. The structure revealed a specific salt link between a Pho85 arginine and a Pho80 aspartate that makes phosphorylation of the Pho85 activation loop dispensable and that maintains a Pho80 loop conformation for possible substrate recognition. It further showed two sites on the Pho80 cyclin for high-affinity binding of the transcription factor substrate (Pho4) and the CDK inhibitor (Pho81) that are markedly distant to each other and the active site.
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.