title: Crystal structure of the human, FIC-domain containing protein HYPE and implications for its functions.
abstract: Protein AMPylation, the transfer of AMP from ATP to protein targets, has been recognized as a new mechanism of host-cell disruption by some bacterial effectors that typically contain a FIC-domain. Eukaryotic genomes also encode one FIC-domain protein,HYPE, which has remained poorly characterized.Here we describe the structure of human HYPE, solved by X-ray crystallography, representing the first structure of a eukaryotic FIC-domain protein. We demonstrate that HYPE forms stable dimers with structurally and functionally integrated FIC-domains and with TPR-motifs exposed for protein-protein interactions. As HYPE also uniquely possesses a transmembrane helix, dimerization is likely to affect its positioning and function in the membrane vicinity. The low rate of auto AMPylation of the wild-type HYPE could be due to autoinhibition, consistent with the mechanism proposed for a number of putative FIC AMPylators. Our findings also provide a basis to further consider possible alternative cofactors of HYPE and distinct modes of target-recognition.
authors.affiliation: Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: t.bunney@ucl.ac.uk.
authors.forename: Tom D
authors.initials: TD
authors.lastname: Bunney
authors.affiliation: Institute of Structural and Molecular Biology, Birkbeck College, London WC1 7HX, UK.
authors.forename: Ambrose R
authors.initials: AR
authors.lastname: Cole
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Broncel
authors.affiliation: Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Diego
authors.initials: D
authors.lastname: Esposito
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Tate
authors.affiliation: Division of Biosciences, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: m.katan@ucl.ac.uk.
authors.forename: Matilda
authors.initials: M
authors.lastname: Katan
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D018360:Crystallography, X-Ray; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D008958:Models, Molecular; D009713:Nucleotidyltransferases; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; C541422:FICD protein, human; D009713:Nucleotidyltransferases