Structural basis of carnitine monooxygenase CntA substrate specificity, inhibition, and intersubunit electron transfer

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

Fersiynau electronig

Dangosydd eitem ddigidol (DOI)

  • Mussa Quareshy
    The University of Warwick
  • Muralidharan Shanmugam
    Central European University, Hungary; University of Manchester, UK; Lund University, Sweden & University of the Aegean, Greece
  • Eleanor Townsend
    The University of Warwick
  • Eleanor Jameson
    School of Health and Life Sciences , Teesside University , Middlesbrough , UKThe University of Warwick
  • Timothy D H Bugg
    The University of Warwick
  • Alexander D Cameron
    The University of Warwick
  • Yin Chen
    The University of Warwick

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 α3 trimeric structure. The two functional domains (the Rieske and the catalytic mononuclear iron domains) are located >40 Å apart in the same monomer but adjacent in two neighboring monomers. Structural determination of CntA and subsequent electron paramagnetic resonance measurements uncover the molecular basis of the so-called bridging glutamate (E205) residue in intersubunit 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 π-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 π-π 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.

Allweddeiriau

Iaith wreiddiolSaesneg
Rhif yr erthygl100038
CyfnodolynJournal of Biological Chemistry
Cyfrol296
Dyddiad ar-lein cynnar4 Ion 2021
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 23 Ion 2021
Cyhoeddwyd yn allanolIe
Gweld graff cysylltiadau