title: Analysis of a Rhizobium leguminosarum gene encoding a protein homologous to glutathione S-transferases.
abstract: A novel Rhizobium leguminosarum gene, gstA, the sequence of which indicated that it was a member of the gene family of glutathione S-transferases (GSTs), was identified. The homology was greatest to the GST enzymes of higher plants. The Rhizobium gstA gene was normally expressed at a very low level. The product of gstA was over-expressed and purified from Escherichia coli. It was shown to bind to the affinity matrix glutathione-Sepharose, but no enzymic GST activity with 1-chloro-2,4-dinitrobenzene as substrate was detected. gstA encoded a polypeptide of 203 amino acid residues with a calculated molecular mass of 21990 Da. Transcribed divergently from gstA is another gene, gstR, which was similar in sequence to the LysR family of bacterial transcriptional regulators. A mutation in gstR had no effect on the transcription of itself or gstA under the growth conditions used here. Mutations in gstA and gstR caused no obvious phenotypic defect and the biological functions of these genes remain to be determined.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Najláa K Tawfiq
authors.initials: NKT
authors.lastname: Alkafaf
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Kay H
authors.initials: KH
authors.lastname: Yeoman
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Margaret
authors.initials: M
authors.lastname: Wexler
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Haitham
authors.initials: H
authors.lastname: Hussain
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Andrew W B
authors.initials: AWB
authors.lastname: Johnston
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D005982:Glutathione Transferase / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D016961:Rhizobium leguminosarum / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C105760:GstA protein, bacteria; D047908:Intracellular Signaling Peptides and Proteins; D005982:Glutathione Transferase