1o9f: Difference between revisions

The fungal phytotoxin fusicoccin stabilizes the interaction between the, C-terminus of the plant plasma membrane H(+)-ATPase and 14-3-3 proteins, thus leading to permanent activation of the proton pump. This results in, an irreversible opening of the stomatal pore, followed by wilting of, plants. Here, we report the crystal structure of the ternary complex, between a plant 14-3-3 protein, fusicoccin and a phosphopeptide derived, from the C-terminus of the H(+)-ATPase. Comparison with the corresponding, binary 14-3-3 complexes indicates no major conformational change induced, by fusicoccin. The compound rather fills a cavity in the, protein-phosphopeptide interaction surface. Isothermal titration, calorimetry indicates that the toxin alone binds only weakly to 14-3-3 and, that peptide and toxin mutually increase each others' binding affinity, approximately 90-fold. These results are important for herbicide, development but might have general implications for drug development, since rather than inhibiting protein-protein interactions, which is, difficult to accomplish, it might be easier to reverse the strategy and, stabilize protein-protein complexes. As the fusicoccin interaction shows, only low-affinity interactions would be required for this strategy.

1O9F is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Nicotiana_tabacum Nicotiana tabacum] with FSC as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1O9F OCA].  

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