title: Cloning and complete nucleotide sequence of the Escherichia coli glutamine permease operon (glnHPQ).
abstract: 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.
mesh_terms: D026923:Amino Acid Transport Systems, Basic; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005796:Genes; D005798:Genes, Bacterial; D005838:Genotype; D008565:Membrane Proteins; D026901:Membrane Transport Proteins / Q000235:genetics*; D009876:Operon; D010957:Plasmids
chemical_list: D026923:Amino Acid Transport Systems, Basic; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C503373:glnP protein, E coli; C037853:glutamine transport proteins; C051432:glutamine permease; D004262:DNA Restriction Enzymes