The RidA protein (PF01042) from is a deaminase that quenches 2-aminoacrylate (2AA) and other reactive metabolites. In the absence of RidA， 2AA accumulates， damages cellular enzymes， and compromises the metabolic network. ， RidA homologs from all domains of life deaminate 2AA， and RidA proteins from plants， bacteria， yeast， and humans complement the mutant phenotype of a mutant strain of In the present study， a methanogenic archaeon， S2， was used to probe alternative mechanisms to restore metabolic balance. MMP0739， which is annotated as an aspartate/glutamate racemase， complemented a mutant strain and reduced the intracellular 2AA burden. The aspartate/glutamate racemase YgeA fro... More
The RidA protein (PF01042) from is a deaminase that quenches 2-aminoacrylate (2AA) and other reactive metabolites. In the absence of RidA， 2AA accumulates， damages cellular enzymes， and compromises the metabolic network. ， RidA homologs from all domains of life deaminate 2AA， and RidA proteins from plants， bacteria， yeast， and humans complement the mutant phenotype of a mutant strain of In the present study， a methanogenic archaeon， S2， was used to probe alternative mechanisms to restore metabolic balance. MMP0739， which is annotated as an aspartate/glutamate racemase， complemented a mutant strain and reduced the intracellular 2AA burden. The aspartate/glutamate racemase YgeA from or ， when provided in ， similarly restored wild-type growth to a mutant. These results uncovered a new mechanism to ameliorate metabolic stress， and they suggest that direct quenching by RidA is not the only strategy to quench 2AA. 2-Aminoacrylate is an endogenously generated reactive metabolite that can damage cellular enzymes if not directly quenched by the conserved deaminase RidA. This study used an archaeon to identify a RidA-independent mechanism to prevent metabolic stress caused by 2AA. The data suggest that a gene product annotated as an aspartate/glutamate racemase (MMP0739) produces a metabolite that can quench 2AA， expanding our understanding of strategies available to quench reactive metabolites.
