InterPro domain: IPR006336

Also known as gamma-glutamylcysteine synthetase and gamma-ECS ( 6.3.2.2 ). This enzyme catalyses the first and rate limiting step in de novo glutathione biosynthesis. Members of this family are found in archaea, bacteria and plants. May and Leaver [ 1 ] discuss the possible evolutionary origins of glutamate-cysteine ligase enzymes in different organisms and suggest that it evolved independently in different eukaryotes, from an ancestral bacterial enzyme. They also state that Arabidopsis thaliana (Mouse-ear cress) gamma-glutamylcysteine synthetase is structurally unrelated to mammalian, yeast and Escherichia coli homologues. In plants, there are separate cytosolic and chloroplast forms of the enzyme.

1. Arabidopsis thaliana gamma-glutamylcysteine synthetase is structurally unrelated to mammalian, yeast, and Escherichia coli homologs. Proc. Natl. Acad. Sci. U.S.A. 91, 10059-63