Cloning and complete nucleotide sequence of the Escherichia coli glutamine permease operon (glnHPQ)

Mol Gen Genet. 1986 Nov;205(2):260-9. doi: 10.1007/BF00430437.


The glutamine permease operon encoding the high-affinity transport system of glutamine in Escherichia coli could be cloned in one of the mini F plasmids, but not in pBR322 or pACYC184, by selection for restoration of the Gln+ phenotype, the ability to utilize glutamine as a sole carbon source. We determined the nucleotide sequence of the glutamine permease operon, which contains the structural gene of the periplasmic glutamine-binding protein (glnH), and indispensable component of the permease activity. The N-terminal amino acid sequence and the overall amino acid composition of the purified glutamine-binding protein were in good agreement with those predicted from the nucleotide sequence, if the N-terminal 22 amino acid residues were discounted. The latter comprised two Lys residues (nos. 2 and 6) followed by 16 hydrophobic amino acid residues and was assumed to be a signal peptide for transport into the periplasmic space. There were two additional reading frames (glnP and glnQ) downstream of glnH sharing a common promoter. It was concluded that the glnP and glnQ proteins as well as the glnH protein are essential for glutamine permease activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Transport Systems, Basic*
  • Base Sequence
  • Carrier Proteins / genetics*
  • Cloning, Molecular*
  • DNA Restriction Enzymes
  • Escherichia coli / genetics*
  • Escherichia coli Proteins
  • Genes*
  • Genes, Bacterial*
  • Genotype
  • Membrane Proteins
  • Membrane Transport Proteins / genetics*
  • Operon*
  • Plasmids


  • Amino Acid Transport Systems, Basic
  • Carrier Proteins
  • Escherichia coli Proteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • glnP protein, E coli
  • glutamine transport proteins
  • glutamine permease
  • DNA Restriction Enzymes