PDBsum entry: 1o9e

Protein binding

PDB id: 1o9e

Contents

Protein chain

232 a.a. *

Ligands

FLC

FSC

Waters ×70

* Residue conservation analysis

PDB id:

1o9e

Name:

Protein binding

Title:

Structural view of a fungal toxin acting on a 14-3-3 regulatory complex

Structure:

14-3-3-like protein c. Chain: a. Engineered: yes. Other_details: gene bank aac49892

Source:

Nicotiana tabacum. Common tobacco. Organism_taxid: 4097. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Dimer (from PDB file)

Resolution:

2.6Å R-factor: 0.222 R-free: 0.258

Authors:

M.Wurtele,C.Jelich-Ottmann,A.Wittinghofer,C.Oecking

Key ref:

M.Würtele et al. (2003). Structural view of a fungal toxin acting on a 14-3-3 regulatory complex. EMBO J, 22, 987-994. PubMed id: 12606564 DOI: 10.1093/emboj/cdg104

Date:

12-Dec-02 Release date: 06-Mar-03

Protein chain

P93343  (1433C_TOBAC) -  14-3-3-like protein C

Seq: 260 a.a.

Struc: 232 a.a.

 Gene Ontology (GO) functional annotation 

• Biochemical function: protein domain specific binding (1 term)

DOI no: 10.1093/emboj/cdg104

EMBO J 22:987-994 (2003)

PubMed id: 12606564

Structural view of a fungal toxin acting on a 14-3-3 regulatory complex.

M.Würtele, C.Jelich-Ottmann, A.Wittinghofer, C.Oecking.

ABSTRACT

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.

Selected figure(s)

Figure 1.
Figure 1 The structure of the fungal toxin fusicoccin.

Figure 4.
Figure 4 The fusicoccin effect. (A) Electrostatic potential surface of 14-3-3, showing the strong charge complementarity of the peptide- binding mode and the more hydrophobic nature of FC binding. Hydrogen bonds are indicated by dashed red lines, and major van der Waals contacts by blue dashed lines. (B) Van der Waals surface representation of the active site, showing the close interaction between the two ligands and how they fill the cavity of 14-3-3.

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (2003, 22, 987-994) copyright 2003.

Figures were selected by an automated process.