Superoxide reductase is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
that
catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycl ...
the conversion of highly reactive and toxic
superoxide
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of ...
(O
2−) into less toxic
hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3% ...
(H
2O
2):
:reduced rubredoxin + O
2− + 2 H
+ rubredoxin + H
2O
2
:Fe
2+ + O
2− + 2 H
+ Fe
3++ H
2O
2
Hydrogen peroxide in turn is reduced to water by
rubrerythrin
Rubrerythrin (RBR) is a non-heme iron-containing metalloprotein involved in oxidative stress tolerance within anaerobic bacteria. It contains a di-iron active site, where peroxide is reduced into two water molecules, and a mono-iron rubredoxin-like ...
. The 3
substrates of this enzyme are
reduced rubredoxin,
superoxide
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of ...
, and
H+, whereas its two
products are
rubredoxin
Rubredoxins are a class of low-molecular-weight iron-containing proteins found in sulfur-metabolizing bacteria and archaea. Sometimes rubredoxins are classified as iron-sulfur proteins; however, in contrast to iron-sulfur proteins, rubredoxins d ...
and
H2O2.
This enzyme belongs to the family of
oxidoreductase
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ...
s, specifically those acting on superoxide as acceptor (only sub-subclass identified to date). The
systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature.
A semisystematic name or semitrivial ...
of this enzyme class is rubredoxin:superoxide oxidoreductase. Other names in common use include neelaredoxin, and desulfoferrodoxin.
Structural studies
, 9
structures have been solved for this class of enzymes, with
PDB accession codes , , , , , , , , and .
References
Further reading
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*
*
EC 1.15.1
Enzymes of known structure
{{1.15-enzyme-stub