Transport of mannose by an inducible phosphoenolpyruvate:fructose phosphotransferase system in Streptococcus salivarius.
Streptococcus salivarius transports mannose by a phosphoenolpyruvate:sugar phosphotransferase system (PTS) which consists of a membrane Enzyme II and two forms of Enzyme III (IIIMan) with molecular masses of 38.9 kDa (IIIManH) and 35.2 kDa (IIIManL) respectively. Using a pseudorevertant (strain 57P) isolated from a IIIManL-deficient spontaneous mutant unable to grow on mannose, we demonstrated that S. salivarius could also transport mannose by an inducible fructose PTS. This PTS phosphorylated fructose at the C-1 position with a high affinity (10 microM) and mannose at the C-6 position with a low affinity (200 microM). Derepression of this system in some IIIManL-deficient mutants would explain their ability to grow on mannose.
Département de biochimie (Sciences), Université Laval, Québec, Canada.
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Pelletier
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Frenette
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Vadeboncoeur
D001667:Binding, Competitive; D001693:Biological Transport, Active; D004790:Enzyme Induction; D005632:Fructose / Q000378:metabolism; D007700:Kinetics; D008358:Mannose / Q000378:metabolism*; D009154:Mutation; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D013291:Streptococcus / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
D005632:Fructose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C061852:phosphoenolpyruvate-mannitol-specific enzyme III; D008358:Mannose