RidA proteins contribute to fitness of S. enterica and E. coli by reducing 2AA stress and moderating flux to isoleucine biosynthesis

• DOI: 10.15698/mic2024.10.837
• Publication Date: 2024-10-22T12:12:33Z
• Authors: Ronnie L. Fulton; Bryce R. Sawyer; Diana M Downs
• Keywords: QH301-705.5; metabolic stress; rida; Biology (General); 2-aminoacrylate; competitive fitness

Abstract Defining the physiological role of a gene product relies on interpreting phenotypes caused by lack, or alteration, respective product. Mutations in critical genes often lead to easily recognized that can include changes cellular growth, metabolism, structure etc. However, mutations many important may fail generate an obvious defect unless additional perturbations are medium genetic background. The latter scenario is exemplified RidA proteins. In vitro proteins deaminate numerous imine/enamines, including those generated serine/threonine dehydratase IlvA (EC:4.3.1.19) from serine threonine – 2-aminoacrylate (2AA) and 2-aminocrotonate (2AC), respectively. Despite this demonstrable biochemical activity, lack has little no effect growth E. coli S. enterica without application metabolic perturbation. A prevent accumulation 2AA which, if allowed persist, irreversibly damage pyridoxal 5’-phosphate (PLP)-dependent enzymes, causing global stress. Because dependent unique each network, link between function stress difficult demonstrate some organisms. current study used coculture experiments exacerbate differences . Results described here solidify established removing 2AA, while also presenting evidence for enhancing flux towards isoleucine biosynthesis Overall, these data emphasize networks distinct responses perturbation, even when individual components conserved.