Analysis of a catabolic operon for sucrose transport and metabolism in Clostridium acetobutylicum ATCC 824.
The utilization of sucrose by Clostridium acetobutylicum ATCC 824 was investigated. Sucrose was found to be transported via a phosphoenol-pyruvate (PEP)-dependent phosphotransferase system (PTS) and a metabolic pathway identical to that previously identified in C. beijerinckii, was established. The genes encoding the proteins of this pathway were identified from the C. acetobutylicum genome sequence, in the order scrAKB encoding Enzyme II of the sucrose PTS, fructokinase and sucrose 6-phosphate hydrolase respectively. While the pathway for sucrose metabolism is conserved between C. acetobutylicum and C. beijerinckii, the operons show considerable differences in organization and regulatory elements. The C. acetobutylicum scr operon contains the elements of an antiterminator-mediated regulation mechanism, typical of the BgIG family of regulators. The scrT gene, located upstream of scrA encodes an antiterminator that is preceded by a transcription terminator, which is overlapped by a classical ribonucleic antiterminator (RAT) sequence. We also propose the existence of a new variant RAT-like sequence which overlaps a terminator between scrT and the downstream structural genes.
Department of Biological Sciences, Heriot-Watt University, Riccarton, Edinburgh, UK. m.tangney@hw.ac.uk
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M
Tangney
W J
WJ
Mitchell
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D003013:Clostridium / Q000235:genetics* / Q000378:metabolism*; D005631:Fructokinases / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon; D012045:Regulatory Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013395:Sucrose / Q000378:metabolism*; D043324:beta-Fructofuranosidase
D001426:Bacterial Proteins; C412834:ScrT protein, Clostridium acetobutylicum; D013395:Sucrose; D005631:Fructokinases; C046173:fructokinase; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase