title: Crystal structure of naphthalene dioxygenase: side-on binding of dioxygen to iron.
abstract: Binding of oxygen to iron is exploited in several biological and chemical processes. Although computational and spectroscopic results have suggested side-on binding, only end-on binding of oxygen to iron has been observed in crystal structures. We have determined structures of naphthalene dioxygenase that show a molecular oxygen species bound to the mononuclear iron in a side-on fashion. In a complex with substrate and dioxygen, the dioxygen molecule is lined up for an attack on the double bond of the aromatic substrate. The structures reported here provide the basis for a reaction mechanism and for the high stereospecificity of the reaction catalyzed by naphthalene dioxygenase.
authors.affiliation: Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, Biomedical Center, 75124 Uppsala, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Karlsson
authors.forename: Juanito V
authors.initials: JV
authors.lastname: Parales
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Parales
authors.forename: David T
authors.initials: DT
authors.lastname: Gibson
authors.forename: Hans
authors.initials: H
authors.lastname: Eklund
authors.forename: S
authors.initials: S
authors.lastname: Ramaswamy
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D018360:Crystallography, X-Ray; D049308:Dioxygenases; D006900:Hydroxylation; D007211:Indoles / Q000378:metabolism; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism*; D009281:Naphthalenes; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D010105:Oxygenases / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D011522:Protons; D011549:Pseudomonas / Q000201:enzymology; D013237:Stereoisomerism
chemical_list: D007211:Indoles; D009097:Multienzyme Complexes; D009281:Naphthalenes; D011522:Protons; C031721:naphthalene; C030374:indole; D007501:Iron; D010105:Oxygenases; D049308:Dioxygenases; C038703:naphthalene dioxygenase; D010100:Oxygen