Iron Based
There are several types of iron based enzymes. Cytochrome cd1, or Pseudomonas cytochrome oxidase contains two c and two d type hemes with two polypeptide chains. Different forms of this reductase catalyze the formation of nitric oxide or nitrous oxide. A version of this compound was originally called . It was initially considered an oxidase. It catalyzes the reduction of NO2- to NO. This tetraheme enzyme has two subunits, each containing a c-type and a d-type heme. The reduced d hemes bind nitrite and convert it to product.
Cytochrome c nitrite reductase (ccNIR) is a multiheme enzyme that converts nitrite to ammonia on each active site. The active site iron is bound to a protoporphyrin IX ring that is covalently linked to the enzyme's proteins.
Read more about this topic: Nitrite Reductase
Famous quotes containing the words iron and/or based:
“For us she is not the iron lady. She is the kind, dear Mrs. Thatcher.”
—Alexander Dubcek (b. 1921)
“Any reductionist program has to be based on an analysis of what is to be reduced. If the analysis leaves something out, the problem will be falsely posed.”
—Thomas Nagel (b. 1938)