5kdp
E491A mutant of choline TMA-lyase
Structural highlights
FunctionCUTC_OLEA2 Glycine radical enzyme that catalyzes the cleavage of a C-N bond in choline, producing trimethylamine (TMA) and acetaldehyde (PubMed:23151509, PubMed:24854437). Is involved in the anaerobic choline utilization pathway that allows D.alaskensis to grow on choline as a source of carbon and energy (PubMed:23151509). Is strictly specific for choline as substrate (PubMed:24854437).[1] [2] Publication Abstract from PubMedDeamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. This work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production. Molecular Basis of C-N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase.,Bodea S, Funk MA, Balskus EP, Drennan CL Cell Chem Biol. 2016 Sep 23. pii: S2451-9456(16)30287-2. doi:, 10.1016/j.chembiol.2016.07.020. PMID:27642068[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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