DROSOPHILA GLUTATHIONE S-TRANSFERASE 1-1 SHARES A REGION OF SEQUENCE HOMOLOGY WITH THE MAIZE GLUTATHIONE S-TRANSFERASE-III

We have characterized a Drosophila glutathione S-transferase (RX:glutathione R-transferase, EC 2.5.1.18) cDNA encoding a protein of 209 amino acids. The cDNA was expressed in Escherichia coli harboring the expression plasmid construct pGTDml-KK. The active enzyme, designated as Drosophila glutathione S-transferase 1-1, had a specific activity toward 1-chloro-2,4-dinitrobenzene comparable to that for the mammalian glutathione S-transferases but did not have as broad a substrate specificity pattern. There is a region of 44 amino acids in this enzyme that shares 66% identity with an analogous region of maize glutathione S-transferase III. Drosophila glutathione S-transferase 1-1 had no obvious homology to any mammalian or parasitic glutathione S-transferases. The gene was found to be a member of a multigene family.