title: Measurement of the proton motive force in Rhizobium meliloti with the Escherichia coli lacY gene product.
abstract: An Escherichia coli lac operon constitutive for lacY was subcloned into the EcoRI site of a wide-host-range plasmid of the Q incompatibility group, and the resulting recombinant plasmid was introduced into Tn5-generated Lac- mutants of Rhizobium meliloti. The R. meliloti transconjugants accumulated lactose about 1,000-fold, equivalent to a proton motive force of -170 to -180 mV, not significantly different from the values calculated from the distributions of weak acids and lipophilic cations.
mesh_terms: D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007763:Lac Operon; D007785:Lactose / Q000378:metabolism*; D008564:Membrane Potentials; D010957:Plasmids; D011522:Protons; D012231:Rhizobium / Q000235:genetics / Q000378:metabolism*
chemical_list: D004274:DNA, Recombinant; D011522:Protons; D007785:Lactose