A hybrid adenosinetriphosphatase composed of F1 of Escherichia coli and F0 of Propionigenium modestum is a functional sodium ion pump.
Analyses on immunoblots indicated strong binding of the alpha- and beta-subunits of the ATPase of Propionigenium modestum to antibodies raised against the corresponding subunits of the F1F0 ATPase of Escherichia coli. Cross-reactivities of antibodies against the other ATPase subunits were not observed. The use of Na+ or H+ as alternate coupling ions, observed previously for the P. modestum ATPase [Laubinger, W., & Dimroth, P. (1989) Biochemistry 28, 7194-7198], is not found for the F1F0 ATPase of E. coli, which is specific for protons. However, a hybrid consisting of the F1 moiety of the E. coli ATPase and F0 of that from P. modestum performed Na+ or H+ transport in a reconstituted system. As with the homologous ATPase of P. modestum, H+ pumping of the hybrid was abolished at Na+ concentrations of greater than 1 mM. The F0 sector and not F1, therefore, determines the cation specificity of these F1F0 ATPases.
Laubinger
W
W
Institut für Physiologische Chemie, Technischen Universität München, FRG.
Deckers-Hebestreit
G
G
Altendorf
K
K
Dimroth
P
P
D001421:Bacteria, Anaerobic / Q000378:metabolism; D001665:Binding Sites; D001693:Biological Transport, Active; D004926:Escherichia coli / Q000378:metabolism; D006824:Hybridization, Genetic; D006859:Hydrogen / Q000378:metabolism; D007700:Kinetics; D011487:Protein Conformation; D011510:Proteolipids; D006180:Proton-Translocating ATPases / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*
D011510:Proteolipids; C020485:proteoliposomes; D006859:Hydrogen; D012964:Sodium; D006180:Proton-Translocating ATPases