Intermediate in the O-O Bond Cleavage Reaction of an Extradiol Dioxygenase.
Kovaleva, E.G., Lipscomb, J.D.(2008) Biochemistry 47: 11168-11170
- PubMed: 18826259 
- DOI: https://doi.org/10.1021/bi801459q
- Primary Citation of Related Structures:  
3ECJ, 3ECK - PubMed 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.
Organizational 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.