2iga

Publication Abstract from PubMed

We report the structures of three intermediates in the O2 activation and insertion reactions of an extradiol ring-cleaving dioxygenase. A crystal of Fe2+-containing homoprotocatechuate 2,3-dioxygenase was soaked in the slow substrate 4-nitrocatechol in a low O2 atmosphere. The x-ray crystal structure shows that three different intermediates reside in different subunits of a single homotetrameric enzyme molecule. One of these is the key substrate-alkylperoxo-Fe2+ intermediate, which has been predicted, but not structurally characterized, in an oxygenase. The intermediates define the major chemical steps of the dioxygenase mechanism and point to a general mechanistic strategy for the diverse 2-His-1-carboxylate enzyme family.

Crystal structures of Fe2+ dioxygenase superoxo, alkylperoxo, and bound product intermediates.,Kovaleva EG, Lipscomb JD Science. 2007 Apr 20;316(5823):453-7. PMID:17446402^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.