title: Intermediate in the O-O bond cleavage reaction of an extradiol dioxygenase.
abstract: The reactive oxy intermediate of the catalytic cycle of extradiol aromatic ring-cleaving dioxygenases is formed by binding the catecholic substrate and O2 in adjacent ligand positions of the active site metal [usually Fe(II)]. This intermediate and the following Fe(II)-alkylperoxo intermediate resulting from oxygen attack on the substrate have been previously characterized in a crystal of homoprotocatechuate 2,3-dioxygenase (HPCD). Here a subsequent intermediate in which the O-O bond is broken to yield a gem diol species is structurally characterized. This new intermediate is stabilized in the crystal by using the alternative substrate, 4-sulfonylcatechol, and the Glu323Leu variant of HPCD, which alters the crystal packing.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, 321 Church Street SE, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Elena G
authors.initials: EG
authors.lastname: Kovaleva
authors.forename: John D
authors.initials: JD
authors.lastname: Lipscomb
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D002396:Catechols / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D005296:Ferrous Compounds / Q000737:chemistry / Q000378:metabolism; D006860:Hydrogen Bonding; D008956:Models, Chemical; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010105:Oxygenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D002396:Catechols; D005296:Ferrous Compounds; D010105:Oxygenases; C439587:extradiol dioxygenase; D010100:Oxygen