Escherichia coli mutants possessing an Li+-resistant melibiose carrier.
Escherichia coli K-12 strains in the absence of the lactose carrier grew on the disaccharide melibiose as the sole source of carbon. The presence of 0.1 mM Li+ in the medium strongly inhibited growth of such cells, and Li+-resistant mutants appeared after several days of incubation. These mutants showed altered cation coupling to melibiose transport via the melibiose carrier. Cotransport between H+ and melibiose was lost in the mutants, although Na+-melibiose cotransport was retained. We observed no Li+-melibiose cotransport. Therefore, these mutants represent a new type of cation-coupling mutants of the melibiose carrier.
D001692:Biological Transport; D004187:Disaccharides / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D008094:Lithium / Q000494:pharmacology*; D008553:Melibiose / Q000378:metabolism*; D009154:Mutation; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology; D013379:Substrate Specificity
D004187:Disaccharides; D008553:Melibiose; D008094:Lithium; D012964:Sodium