An Arabidopsis thaliana cDNA (AtGSHS) encoding a protein with high pri
mary sequence identity to cDNAs previously isolated from Xenopus laevi
s (42%), Schizosaccharomyces pombe (40%), Rattus norvegicus (40%) and
Hemo sapiens (37%) encoding glutathione synthetase (EC 6.3.2.3) has be
en isolated by functional complementation of an Escherichia coli mutan
t deficient in this enzyme, AtGSHS is encoded by a single gene, GSHB,
as determined by Southern blot analysis and the corresponding mRNA is
abundant in both roots and leaves of Arabidopsis.