title: Glutamate residues at positions 219 and 252 in the a-subunit of the Escherichia coli ATP synthase are not functionally equivalent.
abstract: The role of glutamate-219 in the a-subunit of the Escherichia coli F0F1-ATPase was examined using site-directed mutagenesis. The replacement of Glu-219 by lysine, alanine or glycine resulted in a partially functional F0F1-ATPase. Combining any of these mutations with the substitution of glutamate for Gln-252 did not result in any increase in function. These findings rule out a proposal that glutamate at position 252 can functionally replace glutamate at position 219 [S.B. Vik, B.J. Antonio, J. Biol. Chem. 269 (1994) 30364-30369]. All the single and double mutants grew better at 25 degrees C than at 37 degrees C, suggesting a role for Glu-219 in maintaining the structure of the F0.
authors.affiliation: Membrane Biochemistry Group, Division of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Australian National University, P.O. Box 334, Canberra, ACT 0200, Australia. lundall.hatch.anu.edu.au
authors.forename: L P
authors.initials: LP
authors.lastname: Hatch
authors.forename: G B
authors.initials: GB
authors.lastname: Cox
authors.forename: S M
authors.initials: SM
authors.lastname: Howitt
mesh_terms: D002462:Cell Membrane / Q000201:enzymology; D003198:Computer Simulation; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D018698:Glutamic Acid; D006180:Proton-Translocating ATPases