ABSTRACT
Aconitase could also be considered as an oxygen-sensing iron-sulfur protein since its cluster is readily converted to an inactive Fe3S4 cluster in the presence of oxidants. However, this cluster conversion is not accompanied by a change in the protein structure, and its physiological relevance is not clear. The apo form of cyto plasmic aconitase is identical to iron regulatory protein, which acts as an iron sensor. This protein regulates iron storage and uptake by binding to the mRNA of ferritin (an iron storage protein) and transferrin receptor (which transfers iron into the cell); at high iron levels, it incorporates an iron-sulfur cluster and is thus transformed into aconitase, which does not bind RNA anymore.
