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Abstract
The RidA subfamily deaminates imine/enamines, like 2-aminoacrylate (2AA). 2AA is the product of the PLP-dependent serine/ threonine dehydratase IlvA in S. enterica. In absence of RidA, 2AA accumulates and targets PLP-dependent enzymes, permanently inactivating them. A phenotype of 2AA stress in ridA mutants is the inability to grow in the presence of exogenous serine. However, ridA mutants grow in the presence of exogenous serine in static conditions. Phenotypes arising from 2AA stress from endogenous serine pools were not affected by aeration and lack of aeration did not allow for growth of ridA when other sources of 2AA were provided. Data supports that the effect of static growth is specific to increased 2AA from exogenous serine. S. enterica possesses an iron-sulfur cluster dependent serine deaminase SdaA. A ridA sdaA mutant was unable to grow in the presence of exogenous serine in static conditions. These data support a hypothesis that ROS generated during aeration are comprising SdaA, contributing to serine sensitivity.