Non-heme iron protein

In biochemistry, non-heme iron proteins describe families of enzymes that utilize iron at the active site but lack heme cofactors.

Iron-sulfur proteins, including those that are enzymes, are not included in this definition.

Some non-heme iron proteins contain one Fe at their active sites, others have pairs of Fe centers:

Illustrative transformation catalyzed by a non-heme iron protein.
Oxygenation of hemerythrin, a non-heme diiron protein.