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An oxidative N-demethylase reveals PAS transition from ubiquitous sensor to enzyme

Nature volume 539, pages 593597 (24 November 2016) | Download Citation


The universal Per-ARNT-Sim (PAS) domain functions as a signal transduction module involved in sensing diverse stimuli such as small molecules, light, redox state and gases1,2. The highly evolvable PAS scaffold can bind a broad range of ligands, including haem, flavins and metal ions. However, although these ligands can support catalytic activity, to our knowledge no enzymatic PAS domain has been found. Here we report characterization of the first PAS enzyme: a haem-dependent oxidative N-demethylase. Unrelated to other amine oxidases, this enzyme contains haem, flavin mononucleotide, 2Fe-2S and tetrahydrofolic acid cofactors, and specifically catalyses the NADPH-dependent oxidation of dimethylamine. The structure of the α subunit reveals that it is a haem-binding PAS domain, similar in structure to PAS gas sensors3. The dimethylamine substrate forms part of a highly polarized oxygen-binding site, and directly assists oxygen activation by acting as both an electron and proton donor. Our data reveal that the ubiquitous PAS domain can make the transition from sensor to enzyme, suggesting that the PAS scaffold can support the development of artificial enzymes.

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This work was supported by BBSRC grant (BBE0170101). We thank the BBSRC/EPSRC SYNBIOCHEM Centre (grant BB/M017702/1) for access to analytical equipment. We thank the Diamond Light Source for access to beamlines (proposal number MX8997). D.L. is a Royal Society Wolfson Merit Award holder. N.S.S. is an EPSRC Established Career Fellow. The authors acknowledge the use of the Computational Shared Facility and the Protein Structure Facility at The University of Manchester.

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Author notes

    • Pierre Lafite
    •  & Tewes Tralau

    Present addresses : University of Orléans, CNRS, ICOA, UMR 7311, F-45067 Orléans, France (P.L.); German Federal Institute for Risk Assessment (BfR), Department of Chemicals and Product Safety, Max-Dohrn Str. 8-10, 10589 Berlin, Germany (T.T.).


  1. Manchester Institute of Biotechnology, School of Chemistry, 131 Princess Street, University of Manchester, Manchester M1 7DN, UK

    • Mary Ortmayer
    • , Pierre Lafite
    • , Binuraj R. K. Menon
    • , Tewes Tralau
    • , Karl Fisher
    • , Lukas Denkhaus
    • , Nigel S. Scrutton
    • , Stephen E. J. Rigby
    • , Andrew W. Munro
    • , Sam Hay
    •  & David Leys


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M.O. carried out molecular biology, biophysical and structural biology studies on the P. mendocina HODM. M.O. and L.D. carried out purification and characterisation of variant haem domain forms. P.L., B.M. and T.T. were involved in initial screening and solution characterization of HODM homologues. T.T. carried out in vivo formaldehyde detection. K.F. and S.E.J.R. performed and analysed EPR experiments. S.H. performed DFT calculations and kinetic data analysis. All authors discussed the results and participated in writing the manuscript. D.L. initiated and directed this research.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to David Leys.

Reviewer Information Nature thanks P. Ortiz de Montellano, C. Wilmot and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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