Substitution of a single amino acid switches the tentoxin-resistant thermophilic F1-ATPase into a tentoxin-sensitive enzyme.
In contrast to the homologous bacterial and mitochondrial enzymes the chloroplast F(1)-ATPase (CF(1)) is strongly affected by the phytopathogenic inhibitor tentoxin. Based on structural information obtained from crystals of a CF(1)-tentoxin co-complex (Groth, G. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 3464-3468) we have replaced residues betaSer(66) and alphaArg(132) in the alpha(3)beta(3)gamma subcomplex of the thermophilic F(1)-ATPase from Bacillus PS3 by the corresponding residues of the chloroplast ATPase to confer tentoxin sensitivity to the thermophilic enzyme. The mutation alphaArg(132) --> Pro, proposed to relieve steric constraints on tentoxin binding, did not have any significant effect. However, mutation betaSer(66) --> Ala, predicted to provide a crucial hydrogen bond with the inhibitor, resulted in tentoxin inhibition of ATP hydrolysis comparable with the situation found with the chloroplast enzyme.
Groth
Georg
G
Department of Plant Biochemistry, Heinrich-Heine Universitat, D-40225 Dusseldorf, Germany.
Hisabori
Toru
T
Lill
Holger
H
Bald
Dirk
D
D000255:Adenosine Triphosphate / Q000378:metabolism; D019943:Amino Acid Substitution; D001483:Base Sequence; D017931:DNA Primers; D006868:Hydrolysis; D008958:Models, Molecular; D010456:Peptides, Cyclic / Q000494:pharmacology*; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism
D017931:DNA Primers; D010456:Peptides, Cyclic; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; C003384:tentoxin