title: Transcriptional analysis of differential carbohydrate utilization by Clostridium acetobutylicum.
abstract: Transcriptional analysis was performed on Clostridium acetobutylicum with the goal of identifying sugar-specific mechanisms for the transcriptional regulation of transport and metabolism genes. DNA microarrays were used to determine transcript levels from total RNA isolated from cells grown on media containing eleven different carbohydrates, including two pentoses (xylose, arabinose), four hexoses (glucose, mannose, galactose, fructose), four disaccharides (sucrose, lactose, maltose, cellobiose) and one polysaccharide (starch). Sugar-specific induction of many transport and metabolism genes indicates that these processes are regulated at the transcriptional level and are subject to carbon catabolite repression. The results show that C. acetobutylicum utilizes symporters and ATP-binding cassette (ABC) transporters for the uptake of pentose sugars, while disaccharides and hexoses are primarily taken up by phosphotransferase system (PTS) transporters and a gluconate : H(+) (GntP) transporter. The transcription of some transporter genes was induced by specific sugars, while others were induced by a subset of the sugars tested. Sugar-specific transport roles are suggested, based on expression comparisons, for various transporters of the PTS, the ABC superfamily and members of the major facilitator superfamily (MFS), including the GntP symporter family and the glycoside-pentoside-hexuronide (GPH)-cation symporter family. Additionally, updates to the C. acetobutylicum genome annotation are proposed, including the identification of genes likely to encode proteins involved in the metabolism of arabinose and xylose via the pentose phosphate pathway.
authors.affiliation: U S Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Servinsky
authors.affiliation: U S Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Kiel
authors.affiliation: U S Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
authors.forename: Nicole F
authors.initials: NF
authors.lastname: Dupuy
authors.affiliation: U S Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Sund
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D001692:Biological Transport; D050260:Carbohydrate Metabolism; D057465:Catabolite Repression; D046969:Clostridium acetobutylicum / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D020411:Oligonucleotide Array Sequence Analysis; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D018528:ATP-Binding Cassette Transporters; D012329:RNA, Bacterial; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System