Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.2.3 (glutathione synthetase)
 678 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using degenerate oligodeoxyribonucleotide primers based on conserved regions of the cell-division protein FtsZ, a 220-bp fragment of DNA was amplified by the polymerase chain reaction from Anabaena PCC 7120 (Ana). This fragment, which showed significant homology with Escherichia coli ftsZ, was used as a probe to isolate a 15-kb genomic clone containing ftsZ from an Ana DNA library. Sequence analysis revealed an open reading frame (ORF) encoding a protein of 379 amino acids, with 49% identity with E. coli FtsZ. Upstream of Ana ftsZ is a small, unidentified ORF, transcribed in the same direction. An ORF lying downstream of the ftsZ coding region and transcribed in the opposite orientation, shows homology with bacterial glutathione synthetase-encoding genes. Single copies of ftsZ have been identified in Ana and two other cyanobacteria. Multiple transcripts hybridising to ftsZ were detected by Northern hybridisation.
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PMID:Cloning and sequence of ftsZ and flanking regions from the cyanobacterium Anabaena PCC 7120. 755 85

Glutathione is essential for protecting plants from a range of environmental stresses, including heavy metals where it acts as a precursor for the synthesis of phytochelatins. A 1658 bp cDNA clone for glutathione synthetase (gsh2) was isolated from Arabidopsis thaliana plants that were actively synthesizing glutathione upon exposure to cadmium. The sequence of the clone revealed a protein with an estimated molecular mass of 53858 Da that was very similar to the protein from higher eukaryotes, was less similar to the gene from the fission yeast, Schizosaccharomyces pombe, and shared only a small region of similarity with the Escherichia coli protein. A 4.3 kb SstI fragment containing the genomic clone for glutathione synthetase was also isolated and sequenced. A comparison of the cDNA and genomic sequences revealed that the gene was composed of twelve exons. When the Arabidopsis cDNA cloned in a special shuttle vector was expressed in a S. pombe mutant deficient in glutathione synthetase activity, the plant cDNA was able to complement the yeast mutation. Glutathione synthetase activity was measurable in wild-type yeast cells, below detectable levels in the gsh2- mutant, and restored to substantial levels by the expression of the Arabidopsis cDNA. The S. pombe mutant expressing the plant cDNA had near wild type levels of total cellular thiols, 109Cd2+ binding activity, and cadmium resistance. Since the Arabidopsis cDNA was under control of a thiamine-repressible promoter, growth of the transformed yeast on thiamine-free medium increased expression of the cDNA resulting in increases in cadmium resistance.
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PMID:Cloning of the cDNA and genomic clones for glutathione synthetase from Arabidopsis thaliana and complementation of a gsh2 mutant in fission yeast. 891 26

This paper reports that the glutathione (GSH)-deficient mutant, cad2-1, of Arabidopsis is deficient in the first enzyme in the pathway of GSH biosynthesis, gamma-glutamylcysteine synthetase (GCS). The mutant accumulates a substrate of GCS, cysteine, and is deficient in the product, gamma-glutamylcysteine. In vitro enzyme assays showed that the cad2-1 mutant has 40% of wild-type levels of GCS activity but is unchanged in the activity of the second enzyme in the pathway, GSH synthetase. The CAD2 locus maps to chromosome 4 and is tightly linked to a gene, GSHA, identified by a previously isolated cDNA. A genomic clone of GSHA complements both the phenotypic and biochemical deficiencies of the cad2-1 mutant. The nucleotide sequence of the gene has been determined and, in the mutant, this gene contains a 6 bp deletion within an exon. These data demonstrate that the CAD2 gene encodes GCS. The cad2-1 mutation is close to the conserved cysteine which is believed to bind the substrate glutamate and the specific inhibitor L-buthionine-[S,R] sulfoximine (BSO). Both root growth and GCS activity of the cad2-1 mutant was less sensitive than the wild-type to inhibition by BSO, indicating that the mutation may alter the affinity of the inhibitor binding site.
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PMID:The glutathione-deficient, cadmium-sensitive mutant, cad2-1, of Arabidopsis thaliana is deficient in gamma-glutamylcysteine synthetase. 980 29