Experimental verification of a sequence-based prediction: F(1)F(0)-type ATPase of Vibrio cholerae transports protons, not Na(+) ions.
The membrane energetics of the intestinal pathogen Vibrio cholerae involves both H(+) and Na(+) as coupling ions. The sequence of the c subunit of V. cholerae F(0)F(1) ATPase suggested that this enzyme is H(+) specific, in contrast to the results of previous studies on the Na(+)-dependent ATP synthesis in closely related Vibrio spp. Measurements of the pH gradient and membrane potential in membrane vesicles isolated from wild-type and DeltaatpE mutant V. cholerae show that the F(1)F(0) ATPase of V. cholerae is an H(+), not Na(+), pump, confirming the bioinformatics assignments that were based on the Na(+)-binding model of S. Rahlfs and V. Müller (FEBS Lett. 404:269-271, 1999). Application of this model to the AtpE sequences from other bacteria and archaea indicates that Na(+)-specific F(1)F(0) ATPases are present in a number of important bacterial pathogens.
Dzioba
Judith
J
Department of Microbiology, University of Manitoba, Winnipeg, Canada.
Häse
Claudia C
CC
Gosink
Khoosheh
K
Galperin
Michael Y
MY
Dibrov
Pavel
P
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011522:Protons; D016415:Sequence Alignment; D012964:Sodium / Q000378:metabolism*; D014734:Vibrio cholerae / Q000201:enzymology*
D011522:Protons; D006859:Hydrogen; D000255:Adenosine Triphosphate; D012964:Sodium; D006180:Proton-Translocating ATPases