Cloning of the nupC Gene of Escherichia Coli Encoding a Nucleoside Transport System, and Identification of an Adjacent Insertion Element, IS 186

Mol Microbiol. 1994 Mar;11(6):1159-68. doi: 10.1111/j.1365-2958.1994.tb00392.x.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Biological Transport / genetics
  • Carrier Proteins / biosynthesis
  • Carrier Proteins / genetics*
  • Cloning, Molecular
  • Cyclic AMP Receptor Protein / metabolism
  • DNA Transposable Elements / genetics*
  • DNA, Bacterial / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli Proteins*
  • Genes, Bacterial / genetics*
  • Membrane Transport Proteins*
  • Molecular Sequence Data
  • Nucleosides / metabolism*
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Recombinant Proteins / biosynthesis
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Terminator Regions, Genetic


  • Bacterial Proteins
  • Carrier Proteins
  • Cyclic AMP Receptor Protein
  • DNA Transposable Elements
  • DNA, Bacterial
  • Escherichia coli Proteins
  • Membrane Transport Proteins
  • Nucleosides
  • NupC protein, Bacteria
  • NupC protein, E coli
  • Recombinant Proteins

Associated data

  • GENBANK/X74825