%0 Journal Article
%T Rice plants have three homologs of glutathione synthetase genes, one of which, OsGS2, codes for hydroxymethyl©\glutathione synthetase
%A Kumiko Ochiai
%A Shinichi Yamazaki
%A Toru Matoh
%J Archive of "Plant Direct".
%D 2019
%R 10.1002/pld3.119
%X Glutathione is a ubiquitous thiol tripeptide in land plants, and glutathione©\like tripeptides can also be found in some plant species. Rice (Oryza sativa) plants synthesize hydroxymethyl©\glutathione, in which the terminal glycine residue of glutathione is replaced by a serine residue; however, the biosynthetic pathway of hydroxymethyl©\glutathione has not been identified. We isolated three rice glutathione synthetase homologs, designated OsGS1, OsGS2, and OsGS3, and found that knockdown of OsGS2 via RNA interference markedly decreased hydroxymethyl©\glutathione concentration in rice plants. The in vitro enzyme assay, using purified recombinant protein, demonstrated that OsGS2 catalyzed the synthesis of hydroxymethyl©\glutathione from ¦Ă©\glutamylcysteine (¦ĂEC) and L©\serine in an ATP©\dependent manner. OsGS2 could also utilize glycine as a cosubstrate with ¦ĂEC, but the enzyme©\substrate affinity for L©\serine was tenfold higher than that for glycine. These results indicate that OsGS2 codes for hydroxymethyl©\glutathione synthetase
%K glutathione
%K glutathione synthetase
%K hmGSH
%K rice
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6508825/