PMID:15695431

Citation	Ashida, H, Sawa, Y and Shibata, H (2005) Cloning, biochemical and phylogenetic characterizations of gamma-glutamylcysteine synthetase from Anabaena sp. PCC 7120. Plant Cell Physiol. 46:557-62
Abstract	Gamma-glutamylcysteine synthetase (EC 6.3.2.2, gamma-GCS) catalyzes the first step of glutathione synthesis: l-Glu + l-Cys + ATP = gamma-l-glutamyl-l-cysteine (gamma-GC) + ADP + Pi. We have cloned the gene alr3351 of Anabaena sp. PCC 7120, expressed the recombinant enzyme in Escherichia coli, and characterized its product as gamma-GCS by analyzing gamma-GC production, ADP formation and Pi release. Apparent Km values for l-Glu, ATP and l-Cys were estimated to be 0.82, 0.23 and 0.14 mM, respectively. Glutathione and l-buthionine sulfoximine were inhibitors with Ki values of 6.5 and 29.3 mM, respectively. The molecular mass of Anabaena gamma-GCS was estimated to be 43.4 kDa by SDS-PAGE and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The important sequence for the activity of plant gamma-GCS was found in alpha-proteobacterial gamma-GCSs but not in cyanobacterial enzymes, suggesting that the cyanobacterial gamma-GCS gene is not the primary progenitor for the plant genes.
Links	PubMed Online version:10.1093/pcp/pci056
Keywords	Amino Acid Sequence; Anabaena/enzymology; Anabaena/genetics; Cloning, Molecular; Evolution, Molecular; Genetic Variation; Glutamate-Cysteine Ligase/genetics; Glutamate-Cysteine Ligase/metabolism; Molecular Sequence Data; Open Reading Frames/genetics; Phylogeny; Sequence Homology, Amino Acid
edit table

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.