Cloning of the nupC gene of Escherichia coli encoding a nucleoside transport system, and identification of an adjacent insertion element, IS 186.
Escherichia coli is known to contain more than one active transport system for nucleoside uptake. In the present study we report the sequence of a gene encoding a second nucleoside transport system, nupC (in addition to nupG). An open reading frame (ORF) of 1200 bp was identified that codes for a hydrophobic polypeptide of 43,560 Da and an NupC fusion protein was shown to be membrane associated. The native NupC protein is also identified, following over-expression. NupC exhibits short regions of homology to several membrane-associated proteins, including LacY and Cyd. Analysis of the nupC promoter region revealed the presence of at least two putative CRP-binding sites, centred at -40bp and -89bp, which probably flank a CytR-binding site. In addition, an adjacent IS 186 element was identified and found to reside within a putative terminator structure, downstream from the nupC ORF. This arrangement is shown to reflect the previously established gene order on the E. coli chromosome.
Institute of Cell and Molecular Biology, University of Edinburgh, UK.
J E
JE
Craig
Y
Y
Zhang
M P
MP
Gallagher
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial / Q000235:genetics*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009705:Nucleosides / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013728:Terminator Regions, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D009705:Nucleosides; C088081:NupC protein, Bacteria; C490231:NupC protein, E coli; D011994:Recombinant Proteins