title: Post-translational self-hydroxylation: a probe for oxygen activation mechanisms in non-heme iron enzymes.
abstract: Recent years have seen considerable evolution in our understanding of the mechanisms of oxygen activation by non-heme iron enzymes, with high-valent iron-oxo intermediates coming to the forefront as formidably potent oxidants. In the absence of substrate, the generation of vividly colored chromophores deriving from the self-hydroxylation of a nearby aromatic amino acid for a number of these enzymes has afforded an opportunity to discern the conditions under which O2 activation occurs to generate a high-valent iron intermediate, and has provided a basis for a rigorous mechanistic examination of the oxygenation process. Here, we summarize the current evidence for self-hydroxylation processes in both mononuclear non-heme iron enzymes and in mutant forms of ribonucleotide reductase, and place it within the context of our developing understanding of the oxidative transformations accomplished by non-heme iron centers.
authors.affiliation: Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
authors.forename: Erik R
authors.initials: ER
authors.lastname: Farquhar
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Koehntop
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Emerson
authors.forename: Lawrence
authors.initials: L
authors.lastname: Que
mesh_terms: D006900:Hydroxylation; D009154:Mutation; D019159:Nonheme Iron Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012264:Ribonucleotide Reductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D019159:Nonheme Iron Proteins; D012264:Ribonucleotide Reductases; D010100:Oxygen