6gpe

Publication Abstract from PubMed

Lysine degradation has remained elusive in many organisms including Escherichia coli. Here we report catabolism of lysine to succinate in E. coli involving glutarate and L-2-hydroxyglutarate as intermediates. We show that CsiD acts as an alpha-ketoglutarate-dependent dioxygenase catalysing hydroxylation of glutarate to L-2-hydroxyglutarate. CsiD is found widespread in bacteria. We present crystal structures of CsiD in complex with glutarate, succinate, and the inhibitor N-oxalyl-glycine, demonstrating strong discrimination between the structurally related ligands. We show that L-2-hydroxyglutarate is converted to alpha-ketoglutarate by LhgO acting as a membrane-bound, ubiquinone-linked dehydrogenase. Lysine enters the pathway via 5-aminovalerate by the promiscuous enzymes GabT and GabD. We demonstrate that repression of the pathway by CsiR is relieved upon glutarate binding. In conclusion, lysine degradation provides an important link in central metabolism. Our results imply the gut microbiome as a potential source of glutarate and L-2-hydroxyglutarate associated with human diseases such as cancer and organic acidurias.

Widespread bacterial lysine degradation proceeding via glutarate and L-2-hydroxyglutarate.,Knorr S, Sinn M, Galetskiy D, Williams RM, Wang C, Muller N, Mayans O, Schleheck D, Hartig JS Nat Commun. 2018 Nov 29;9(1):5071. doi: 10.1038/s41467-018-07563-6. PMID:30498244^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.