InterPro domain: IPR024134

Superoxide dismutases (SODs) are ubiquitous metalloproteins that prevent damage by oxygen-mediated free radicals by catalysing the dismutation of superoxide into molecular oxygen and hydrogen peroxide [ 1 ]. Superoxide is a normal by-product of aerobic respiration and is produced by a number of reactions, including oxidative phosphorylation and photosynthesis. The dismutase enzymes have a very high catalytic efficiency due to the attraction of superoxide to the ions bound at the active site [ 2 , 3 ].

There are three forms of superoxide dismutase, depending on the metal cofactor: Cu/Zn (which binds both copper and zinc), Fe and Mn types. The Fe and Mn forms are similar in their primary, secondary and tertiary structures, but are distinct from the Cu/Zn form [ 4 ]. Prokaryotes and protists contain Mn, Fe or both types, while most eukaryotic organisms utilise the Cu/Zn type.

This entry represents the superoxide dismutase proteins as well as a related family of copper chaperones for superoxide dismutases. These cytosolic proteins deliver copper to Cu/Zn superoxide dismutases and are vital to their function [ 5 ].

1. Primary structure from amino acid and cDNA sequences of two Cu,Zn superoxide dismutase variants from Xenopus laevis. Arch. Biochem. Biophys. 272, 507-15
2. Atomic structures of wild-type and thermostable mutant recombinant human Cu,Zn superoxide dismutase. Proc. Natl. Acad. Sci. U.S.A. 89, 6109-13
3. Primary structure of porcine Cu,Zn superoxide dismutase. FEBS Lett. 186, 267-70
4. Characterization of iron superoxide dismutase cDNAs from plants obtained by genetic complementation in Escherichia coli. Proc. Natl. Acad. Sci. U.S.A. 87, 9903-7
5. Copper chaperone for superoxide dismutase is essential to activate mammalian Cu/Zn superoxide dismutase. Proc. Natl. Acad. Sci. U.S.A. 97, 2886-91