YdiU regulates Salmonella Oxidative Stress by UMPylation of SodA

The expression of ydiU was dramatically induced by hydrogen peroxide (H2O2) and the survivability of △ydiU was significantly stronger than that of WT under oxidative stress. Interestingly, in vitro and in vivo experiments showed that YdiU can interact with SodA and UMPylate it only in the presence of H2O2.  Further study showed slight changes in the secondary structure of SodA under oxidative stress. Structural analysis of native protein and H2O2-treated protein showed that H2O2 treatment affected the conformation of Met24.  The modification site Tyr12 is near Met24, and Tyr12 exposure may facilitate UMPylation by YdiU after H2O2 treatment.