Abstract

Deciphering the Role of Multiple Glyoxalase I Enzymes of Different Metal Classes in Arabidopsis

Ananda Mustafiz, Assistant Professor, South Asian University

Glyoxalase pathway is ubiquitously found in all organisms ranging from prokaryotes to eukaryotes. It acts as a major pathway for the detoxification of methlyglyoxal (MG) in the living system. It consists of two important enzymes Glyoxalase I (GLY I) and Glyoxalase II (GLY II). GLY I is the first important enzyme of this system and is characterized into two metal activation classes, Zn2+dependent and non-Zn2+ dependent. For the first time the presence of multiple active GLY I enzymes belonging to different metal activation classes in higher eukaryotic species is reported here. The three active GLY I enzymes (AtGLYI2, AtGLYI3 and AtGLYI6) belonging to different metal activation classes coexist in Arabidopsis thaliana. These enzymes have been found to efficiently complement the GLY I yeast mutants and have been characterized in terms of their activity, metal dependency, kinetic parameters and their role in conferring tolerance to multiple abiotic stresses in E. coli. The activity of these GLY I enzymes correlated well to their role in stress tolerance. Heterologous expression of these enzymes in E. coli led to better tolerance against various stress conditions. The role of individual metal dependent GLY I genes in response to various abiotic stresses in plant system will be explored in future.