Nucleotide sequence of gltS, the Na+/glutamate symport carrier gene of Escherichia coli B.
The nucleotide sequence of the gltS gene coding for an Na+/glutamate symport carrier of Escherichia coli B has been determined, and the amino acid sequence of the carrier protein was deduced. The predicted glutamate carrier consists of 401 amino acids with a molecular weight of 42,455. A Shine-Dalgarno sequence and putative promoter sequences were found in the 5'-flanking region of the putative gltS gene. The predicted protein is very hydrophobic (73% nonpolar amino acids), and judging from its hydropathy profile, the protein is composed of 12 hydrophobic membrane-spanning segments with a mean length of 21.6 residues/segment. A typical rho-independent transcription termination signal was found downstream of the gltS gene. We found a conserved alignment of 5 amino acid residues (Gly42--Ala82-X-X-X-X-Leu87-X-X-X-Gly91-Arg92 ), which commonly exists in four Na+ symport carrier proteins, the glutamate carrier, and the proline carrier of E. coli, and the Na+/glucose co-transporters of rabbit and human intestines. We propose that this consensus sequence (or motif) may play an important role in cation recognition or binding in the Na+/solute symport reaction.
Deguchi
Y
Y
Department of Biology, Faculty of Science, University of Tokyo, Japan.
Yamato
I
I
Anraku
Y
Y
D000595:Amino Acid Sequence; D026922:Amino Acid Transport Systems, Acidic; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D005971:Glutamates / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012995:Solubility; D027981:Symporters; D013728:Terminator Regions, Genetic
D026922:Amino Acid Transport Systems, Acidic; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D005971:Glutamates; D008565:Membrane Proteins; D027981:Symporters; C066603:gltS protein, E coli