title: Identification and characterization of gshA, a gene encoding the glutamate-cysteine ligase in the halophilic archaeon Haloferax volcanii.
abstract: Halophilic archaea were found to contain in their cytoplasm millimolar concentrations of gamma-glutamylcysteine (gamma GC) instead of glutathione. Previous analysis of the genome sequence of the archaeon Halobacterium sp. strain NRC-1 has indicated the presence of a sequence homologous to sequences known to encode the glutamate-cysteine ligase GshA. We report here the identification of the gshA gene in the extremely halophilic archaeon Haloferax volcanii and show that H. volcanii gshA directs in vivo the synthesis and accumulation of gamma GC. We also show that the H. volcanii gene when expressed in an Escherichia coli strain lacking functional GshA is able to restore synthesis of glutathione.
authors.affiliation: Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Liron
authors.initials: L
authors.lastname: Malki
authors.forename: Michaela
authors.initials: M
authors.lastname: Yanku
authors.forename: Ilya
authors.initials: I
authors.lastname: Borovok
authors.forename: Gerald
authors.initials: G
authors.lastname: Cohen
authors.forename: Moshe
authors.initials: M
authors.lastname: Mevarech
authors.forename: Yair
authors.initials: Y
authors.lastname: Aharonowitz
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D004151:Dipeptides / Q000378:metabolism; D019848:Gene Expression Regulation, Archaeal / Q000235:genetics / Q000502:physiology; D005816:Genetic Complementation Test; D005721:Glutamate-Cysteine Ligase / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000502:physiology*; D019622:Haloferax volcanii / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D019843:Archaeal Proteins; D004151:Dipeptides; D005721:Glutamate-Cysteine Ligase; C017341:gamma-glutamylcysteine