Sequencing and characterization of the sdaC gene and identification of the sdaCB operon in Escherichia coli K12.
We describe here the regulatory and coding region, and DNA sequence, for a newly recognized gene, sdaC, which codes for a hydrophobic protein with several predicted membrane-spanning domains. sdaC and sdaB form a single operon, with 57 bp between the end of sdaC and the start of sdaB. Expression of the sdaCB operon is regulated mainly by catabolite repression, but is also slightly sensitive to regulation by leucine-responsive regulatory protein. Cells carrying sdaC on a multicopy plasmid have increased L-serine transport capacity, insensitive to threonine, suggesting that sdaC might code for a recently described highly specific serine transporter [Kayahara, T., Thelen, P., Ogawa, W., Inaba, K., Tsuda, M., Goldberg, E. B. & Tsuchiya, T. (1992) J. Bacteriol. 174, 7482-7485].
Shao
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Biology Department, Concordia University, Montreal, Canada.
Lin
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RT
Newman
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EB
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D051756:Leucine-Responsive Regulatory Protein; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon; D010957:Plasmids; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C497278:Lrp protein, E coli; D008565:Membrane Proteins; C088329:SdaC protein, E coli; D014157:Transcription Factors; D051756:Leucine-Responsive Regulatory Protein; D013912:Threonine; D012694:Serine