title: Anaerobic transport of amino acids coupled to the glycerol-3-phosphate-fumarate oxidoreductase system in a cytochrome-deficient mutant of Escherichia coli.
abstract: The uptake of proline and glutamine by cytochrome-deficient cells of Escherichia coli SASX76 grown aerobically on glucose or anaerobically on pyruvate was stimulated by these two substrates. Pyruvate could not stimulate transport in the glucose-grown cells. Uptake of these amino acids energized by glucose was inhibited by inhibitors of the Ca2+, Mg2+-stimulated ATPase such as DCCD, pyrophosphate, and azide, and by the uncouplers CCCP and 2,4-dinitrophenol. Glycerol (or glycerol 3-phosphate) in the presence of fumarate stimulated the transport of proline and glutamine under anaerobic conditions in cytochrome-deficient cells but not in membrane vesicles prepared from these cells although glycerol 3-phosphate-fumarate oxidoreductase activity could be demonstrated in the vesicle preparation. In contrast, in vesicles prepared from cytochrome-containing cells of E. coli SASX76 amino acid transport was energized under anaerobic conditions by this system. Inhibitors of the Ca2+, Mg2+-activated ATPase and uncoupling agents inhibited the uptake of proline and glutamine in cytochrome-deficient cells dependent on the glycerol-fumarate oxidoreductase system. Ferricyanide could replace fumarate as an electron acceptor to permit transport of phenylalanine in cytochrome-deficient or cytochrome-containing cells under anaerobic conditions. It is concluded that in cytochrome-deficient cells using glucose, pyruvate, or glycerol in the presence of fumarate, transport of both proline and glutamine under under anaerobic conditions is energized by ATP through the Ca2+, Mg2+-activated ATPase. In cytochrome-containing cells under anaerobic conditions electron transfer between glycerol and fumarate can also drive transport of these amino acids.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000693:Anaerobiosis; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D005292:Ferricyanides / Q000494:pharmacology; D005650:Fumarates / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D005973:Glutamine / Q000378:metabolism; D005990:Glycerol / Q000494:pharmacology; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D011773:Pyruvates / Q000494:pharmacology; D013386:Succinates / Q000378:metabolism; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D003580:Cytochromes; D005292:Ferricyanides; D005650:Fumarates; D011773:Pyruvates; D013386:Succinates; D014475:Uncoupling Agents; D005973:Glutamine; D010649:Phenylalanine; D000255:Adenosine Triphosphate; D011392:Proline; D010088:Oxidoreductases; D005993:Glycerolphosphate Dehydrogenase; D000251:Adenosine Triphosphatases; D005947:Glucose; D005990:Glycerol