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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.

SUBMITTER: Kovaleva EG

PROVIDER: S-EPMC2629449 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

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Intermediate in the O-O bond cleavage reaction of an extradiol dioxygenase.

Kovaleva Elena G EG Lipscomb John D JD

Biochemistry 20081001 43

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 t ...[more]

PMID: 18826259

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