The ups and downs of ectoine: structural enzymology of a major microbial stress protectant and versatile nutrient

摘要: Ectoine and its derivative 5-hydroxyectoine are compatible solutes chemical chaperones widely synthesized by Bacteria some Archaea as cytoprotectants during osmotic stress high- or low-growth temperature extremes. The function-preserving attributes of ectoines led to numerous biotechnological biomedical applications fostered the development an industrial scale production process. Synthesis requires expenditure considerable energetic biosynthetic resources. Hence, microorganisms have developed ways exploit nutrients when they no longer needed protectants. Here, we summarize our current knowledge on phylogenomic distribution ectoine producing consuming microorganisms. We emphasize structural enzymology pathways underlying biosynthesis consumption, understanding that has been achieved only recently. synthesis degradation critically differ in isomeric form key metabolite N-acetyldiaminobutyric acid (ADABA). γ-ADABA serves preferred substrate for synthase, while α-ADABA isomer is produced hydrolase intermediate catabolism. It can serve internal inducer genetic control catabolic genes via GabR/MocR-type regulator EnuR. Our review highlights importance inspire mechanistic metabolic networks at biological scale.