title: Global transcriptional analysis of Streptococcus mutans sugar transporters using microarrays.
abstract: The transport of carbohydrates by Streptococcus mutans is accomplished by the phosphoenolpyruvate-phosphotransferase system (PTS) and ATP-binding cassette (ABC) transporters. To undertake a global transcriptional analysis of all S. mutans sugar transporters simultaneously, we used a whole-genome expression microarray. Global transcription profiles of S. mutans UA159 were determined for several monosaccharides (glucose, fructose, galactose, and mannose), disaccharides (sucrose, lactose, maltose, and trehalose), a beta-glucoside (cellobiose), oligosaccharides (raffinose, stachyose, and maltotriose), and a sugar alcohol (mannitol). The results revealed that PTSs were responsible for transport of monosaccharides, disaccharides, beta-glucosides, and sugar alcohol. Six PTSs were transcribed only if a specific sugar was present in the growth medium; thus, they were regulated at the transcriptional level. These included transporters for fructose, lactose, cellobiose, and trehalose and two transporters for mannitol. Three PTSs were repressed under all conditions tested. Interestingly, five PTSs were always highly expressed regardless of the sugar source used, presumably suggesting their availability for immediate uptake of most common dietary sugars (glucose, fructose, maltose, and sucrose). The ABC transporters were found to be specific for oligosaccharides, raffinose, stachyose, and isomaltosaccharides. Compared to the PTSs, the ABC transporters showed higher transcription under several tested conditions, suggesting that they might be transporting multiple substrates.
authors.affiliation: University of Oklahoma Health Sciences Center, Department of Microbiology and Immunology, 940 S. L. Young Blvd., Oklahoma City, OK 73104, USA. dragana-ajdic@ouhsc.edu
authors.forename: Dragana
authors.initials: D
authors.lastname: Ajdić
authors.forename: Vi T T
authors.initials: VT
authors.lastname: Pham
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001692:Biological Transport / Q000235:genetics; D002241:Carbohydrates / Q000493:pharmacokinetics; D002475:Cellobiose / Q000378:metabolism / Q000493:pharmacokinetics; D005632:Fructose / Q000378:metabolism / Q000493:pharmacokinetics; D005690:Galactose / Q000378:metabolism / Q000493:pharmacokinetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics; D007785:Lactose / Q000378:metabolism / Q000493:pharmacokinetics; D008320:Maltose / Q000378:metabolism / Q000493:pharmacokinetics; D008358:Mannose / Q000378:metabolism / Q000493:pharmacokinetics; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D009844:Oligosaccharides / Q000378:metabolism / Q000493:pharmacokinetics; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D011887:Raffinose / Q000378:metabolism / Q000493:pharmacokinetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000235:genetics* / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism / Q000493:pharmacokinetics; D014158:Transcription, Genetic; D014312:Trisaccharides / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D018528:ATP-Binding Cassette Transporters; D002241:Carbohydrates; D009844:Oligosaccharides; D014312:Trisaccharides; D002475:Cellobiose; C005695:stachyose; D005632:Fructose; D013395:Sucrose; C008317:maltotriose; D008320:Maltose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D005947:Glucose; D007785:Lactose; D011887:Raffinose; D008358:Mannose; D005690:Galactose