Iron–sulfur proteins

Nitrogenases are enzymes () that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria. These enzymes are responsible for the reduction of nitrogen (N2) to ammonia (NH3). Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a step in the process of nitrogen fixation. Nitrogen fixation is required for all forms of life, with nitrogen being essential for the biosynthesis of molecules (nucleotides, amino acids) that create plants, animals and other organisms. They are encoded by the Nif genes or homologs. They are related

class of enzymes

Ferredoxins (from Latin ferrum: iron + redox, often abbreviated "fd") are iron–sulfur proteins that mediate electron transfer in a range of metabolic reactions. They contain iron and sulfur atoms organized as iron–sulfur clusters. These biomolecules accept or discharge electrons, with the effect of a change in the oxidation state of the iron atoms between +2 and +3, letting them act as electron transfer agents in biological redox reactions.

A hydrogenase is an enzyme that catalyses the reversible oxidation of molecular hydrogen (H2), as shown below:

class of proteins in which iron is coordinated with cysteine sulfur and also with inorganic sulfur

Complex that transfers electrons from reduced plastoquinone to oxidized plastocyanin and translocates protons from the stroma to the lumen

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 do not contain inorganic sulfide. Like cytochromes, ferredoxins and Rieske proteins, rubredoxins are thought to participate in electron transfer in biological systems. Recent work in bacteria and algae have led to the hypothesis that some rubredoxins may instead have a role in delivering iron to metalloproteins.

protein family with an iron–sulfur center transferring electrons