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)-alkyl-peroxo 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.
Original language | English (US) |
---|---|
Pages (from-to) | 11168-11170 |
Number of pages | 3 |
Journal | Biochemistry |
Volume | 47 |
Issue number | 43 |
DOIs | |
State | Published - Oct 28 2008 |