title: Dual control of a common L-1,2-propanediol oxidoreductase by L-fucose and L-rhamnose in Escherichia coli.
abstract: Anaerobic growth of Escherichia coli on L-fucose or L-rhamnose as the sole source of carbon and energy depends on the regeneration of NAD from NADH by disposing the intermediate L-lactaldehyde as L-1,2-propanediol. The two parallel pathways, with their own permeases and enzymes encoded by two widely separated gene clusters, appear to share a single enzyme that catalyzes the formation of L-1,2-propanediol. Although this oxidoreductase is encoded by a gene at the fuc locus, the enzyme is inducible by both L-fucose and L-rhamnose. The inducibility by L-rhamnose is controlled by a gene at the rha locus with no other known functions, since the aerobic growth rate on L-rhamnose remains normal. L-1,2-Propanediol oxidoreductase activity is inducible only anaerobically, and the effect of the two methylpentoses operates at different levels: L-fucose exerts its influence post-transcriptionally; L-rhamnose exerts its influence transcriptionally.
mesh_terms: D000332:Aerobiosis; D000429:Alcohol Oxidoreductases / Q000096:biosynthesis*; D000693:Anaerobiosis; D004274:DNA, Recombinant; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005643:Fucose / Q000378:metabolism / Q000494:pharmacology*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005809:Genes, Regulator; D009154:Mutation; D012210:Rhamnose / Q000378:metabolism / Q000494:pharmacology*; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D004274:DNA, Recombinant; D005643:Fucose; D000429:Alcohol Oxidoreductases; C021494:lactaldehyde reductase; D001616:beta-Galactosidase; D012210:Rhamnose