title: Domain mobility as probed by small-angle X-ray scattering may account for substrate access to the active site of two copper-dependent amine oxidases.
abstract: Amine oxidases are a family of dimeric enzymes that contain one copper(II) ion and one 2,4,5-trihydroxyphenyalanine quinone per subunit. Here, the low-resolution structures of two Cu/TPQ amine oxidases from lentil (Lens esculenta) seedlings and from Euphorbia characias latex have been determined in solution by small-angle X-ray scattering. The active site of these enzymes is highly buried and requires a conformational change to allow substrate access. The study suggests that the funnel-shaped cavity located between the D3 and D4 domains is narrower within the crystal structure, whereas in solution the D3 domain could undergo movement resulting in a protein conformational change that is likely to lead to easier substrate access.
authors.affiliation: Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Dainese
authors.affiliation: Faculty of Bioscience and Technology for Food Agriculture and Environment, University of Teramo, Teramo, Italy.
authors.forename: Annalaura
authors.initials: A
authors.lastname: Sabatucci
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cagliari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pintus
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cagliari, Italy.
authors.forename: Rosaria
authors.initials: R
authors.lastname: Medda
authors.affiliation: Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy.
authors.forename: Clotilde Beatrice
authors.initials: CB
authors.lastname: Angelucci
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cagliari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Floris
authors.affiliation: European Center for Brain Research (CERC)/Santa Lucia Foundation, Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Maccarrone
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D020134:Catalytic Domain; D003300:Copper / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D053838:Scattering, Small Angle; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D003300:Copper; D006631:Amine Oxidase (Copper-Containing)
keywords: SAXS; TOPA; TPQ; amine oxidase; conformational change; copper; domain movement