1KMH: Crystal Structure Of Spinach Chloroplast F1-atpase Complexed With Tentoxin

Tentoxin, a natural cyclic tetrapeptide produced by phytopathogenic fungi from the Alternaria species affects the catalytic function of the chloroplast F(1)-ATPase in certain sensitive species of plants. In this study, we show that the uncompetitive inhibitor tentoxin binds to the alphabeta-interface of the chloroplast F(1)-ATPase in a cleft localized at betaAsp-83. Most of the binding site is located on the noncatalytic alpha-subunit. The crystal structure of the tentoxin-inhibited CF(1)-complex suggests that the inhibitor is hydrogen bonded to Asp-83 in the catalytic beta-subunit but forms hydrophobic contacts with residues Ile-63, Leu-65, Val-75, Tyr-237, Leu-238, and Met-274 in the adjacent alpha-subunit. Except for minor changes around the tentoxin-binding site, the structure of the chloroplast alpha(3)beta(3)-core complex is the same as that determined with the native chloroplast ATPase. Tentoxin seems to act by inhibiting inter-subunit contacts at the alphabeta-interface and by blocking the interconversion of binding sites in the catalytic mechanism.
PDB ID: 1KMHDownload
MMDB ID: 19003
PDB Deposition Date: 2001/12/16
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 3.4  Å
Source Organism:
Similar Structures:
Biological Unit for 1KMH: dimeric; determined by author and by software (PISA)
Molecular Components in 1KMH
Label Count Molecule
Proteins (2 molecules)
Atpase Alpha Subunit(Gene symbol: atpA)
Molecule annotation
Atpase Beta Subunit(Gene symbol: atpB)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB