Eukaryotic copper-only superoxide dismutases (SODs): A new class of SOD enzymes and SOD-like protein domains

Natalie G. Robinett, Ryan L. Peterson, Valeria L Culotta

Research output: Contribution to journalReview article

Abstract

The copper-containing superoxide dismutases (SODs) represent a large family of enzymes that participate in the metabolism of reactive oxygen species by disproportionating superoxide anion radical to oxygen and hydrogen peroxide. Catalysis is driven by the redox-active copper ion, and in most cases, SODs also harbor a zinc at the active site that enhances copper catalysis and stabilizes the protein. Such bimetallic Cu,Zn-SODs are widespread, from the periplasm of bacteria to virtually every organelle in the human cell. However, a new class of copper-containing SODs has recently emerged that function without zinc. These copper-only enzymes serve as extracellular SODs in specific bacteria (i.e. Mycobacteria), throughout the fungal kingdom, and in the fungus-like oomycetes. The eukaryotic copper-only SODs are particularly unique in that they lack an electrostatic loop for substrate guidance and have an unusual open-access copper site, yet they can still react with superoxide at rates limited only by diffusion. Copper-only SOD sequences similar to those seen in fungi and oomycetes are also found in the animal kingdom, but rather than single-domain enzymes, they appear as tandem repeats in large polypeptides we refer to as CSRPs (copper-only SOD-repeat proteins). Here, we compare and contrast the Cu,Zn versus copper-only SODs and discuss the evolution of copper-only SOD protein domains in animals and fungi.

Original languageEnglish (US)
Pages (from-to)4636-4643
Number of pages8
JournalJournal of Biological Chemistry
Volume293
Issue number13
DOIs
Publication statusPublished - Jan 1 2018

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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