6y9d

Crystal structure of the quaternary ammonium Rieske monooxygenase CntA in complex with substrate L-Carnitine

spinqualitylabelsall models 6y9d, resolution 1.97Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6y9d is a 12 chain structure with sequence from Acinetobacter baumannii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.97Å Ligands: 152, EPE, FE, FES, SCN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A059ZPP5_ACIBA Converts carnitine to trimethylamine and malic semialdehyde.[HAMAP-Rule:MF_02097] Publication Abstract from PubMed Microbial metabolism of carnitine to trimethylamine (TMA) in the gut can accelerate atherosclerosis and heart disease and these TMA-producing enzymes are therefore important drug targets. Here, we report the first structures of the carnitine oxygenase CntA, an enzyme of the Rieske oxygenase family. CntA exists in a head-to-tail a3 trimeric structure. The two functional domains (the Rieske and the catalytic mononuclear iron domains) are located > 40 A apart in the same monomer but adjacent in two neighbouring monomers. Structural determination of CntA and subsequent electron paramagnetic resonance measurements uncover the molecular basis of the so-called bridging glutamate (E205) residue in inter-subunit electron transfer. The structures of the substrate-bound CntA help to define the substrate pocket. Importantly, a tyrosine residue (Y203) is essential for ligand recognition through a pi-cation interaction with the quaternary ammonium group. This interaction between an aromatic residue and quaternary amine substrates allows us to delineate a subgroup of Rieske oxygenases (group V) from the prototype ring-hydroxylating Rieske oxygenases involved in bioremediation of aromatic pollutants in the environment. Furthermore, we report the discovery of the first known CntA inhibitors and solve the structure of CntA in complex with the inhibitor, demonstrating the pivotal role of Y203 through a pi-pi stacking interaction with the inhibitor. Our study provides the structural and molecular basis for future discovery of drugs targeting this TMA-producing enzyme in human gut. Structural basis of carnitine monooxygenase CntA substrate specificity, inhibition and inter-subunit electron transfer.,Quareshy M, Shanmugam M, Townsend E, Jameson E, Bugg TDH, Cameron AD, Chen Y J Biol Chem. 2020 Nov 6. pii: RA120.016019. doi: 10.1074/jbc.RA120.016019. PMID:33158989 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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