Molecule of the Month: Hsp90
Heat shock proteins ensure that proteins remain folded and active under harsh conditions
Exploring the Structure
HSP90 N-terminal Domain (PDB entries 1am1 and 1yet)
The first compound found to attack Hsp90 is a natural product called geldanamycin made by Streptomyces bacteria, shown here on the right from PDB entry 1yet . It binds in the ATP-binding site on Hsp90, blocking the binding of ATP and thus freezing the large conformational changes needed for function. The structure of ATP bound in this site is shown on the left from PDB entry 1am1 (when you look at this structure yourself, note that only two of the three phosphates are included in the atomic coordinates; the third one is disordered). Unfortunately, geldanamycin is too toxic for use as an anticancer drug, but many better compounds have been developed since then. To explore this structure in more detail, click on the image to view an interactive JSmol.
Topics for Further Discussion
- Can you find other structures of Hsp90 with experimental drug molecules?
- Geldanamycin looks very different than ATP, but it turns out that it makes similar contacts with the protein binding site. Can you find the amino acids that directly interact with ATP and with geldanamycin?
Related PDB-101 Resources
- Browse Protein Synthesis
- Browse Cancer
- L. H. Pearl, C. Prodromou and P. Workman (2008) The Hsp90 molecular chaperone: and open and shut case for treatment. Biochemical Journal 410, 439-453.
- D. B. Solit and G. Choisis (2008) Development and application of Hsp90 inhibitors. Drug Discovery Today 13, 38-43.
- S. K. Wandlinger, K. Richter and J. Buchner (2008) The Hsp90 chaperone machinery. Journal of Biological Chemistry 283, 18473-18477.
- L. H. Pearl and C. Prodromou (2006) Structure and mechanism of the Hsp90 molecular chaperone machinery. Annual Review of Biochemistry 75, 271-294.
December 2008, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2008_12