title: Isolation of a novel protein involved in the transport of fructose by an inducible phosphoenolpyruvate fructose phosphotransferase system in Streptococcus mutans.
abstract: Fructose transport in Streptococcus mutans LG-1 is mediated by at least two distinct phosphoenolpyruvate fructose phosphotransferase systems. One system is constitutive and consists of membrane components enzyme II as well as enzyme I and heat-stable protein. The other system is inducible and requires, in addition to enzyme I and heat-stable protein, a soluble substrate-specific protein for catalytic activity. This protein factor, designated IIIfru, was purified by DEAE-cellulose chromatography, hydroxylapatite chromatography, molecular sieving on Sephadex G-75, and preparative electrophoresis. The purified preparation showed only one protein band, with a molecular weight of 12,600, on sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis, on gel electrophoresis with the discontinuous buffer Tris-glycine, and after electrofocusing in gel (pI congruent to 3.7). The molecular weight of the native protein determined by gel filtration at 4 degrees C was 51,000. Immunodiffusion experiments performed with immunoglobulins prepared against the purified IIIfru from S. mutans LG-1 suggested that other S. mutans strains possessed a IIIfru. No precipitin bands, however, were detected with extracts from S. salivarius, S. sanguis, S. lactis, S. faecalis, Staphylococcus aureus, Bacillus subtilis, Lactobacillus casei, and Escherichia coli.
mesh_terms: D001693:Biological Transport, Active; D002462:Cell Membrane / Q000201:enzymology; D004790:Enzyme Induction; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D007527:Isoenzymes / Q000096:biosynthesis / Q000302:isolation & purification; D007700:Kinetics; D008970:Molecular Weight; D009005:Monosaccharides / Q000378:metabolism; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000096:biosynthesis* / Q000302:isolation & purification; D013295:Streptococcus mutans / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D009005:Monosaccharides; D005632:Fructose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D005947:Glucose