|PROSITE documentation PDOC00085 [for PROSITE entry PS00090]|
Nitrogenase (EC 220.127.116.11)  is the enzyme system responsible for biological nitrogen fixation. Nitrogenase is an oligomeric complex which consists of two components: component 2 is an homodimer of an iron-sulfur protein, while component 1 which contains the active site for the reduction of nitrogen to ammonia exists in three different forms:
The α and β chains of the three types of component 1 are evolutionary related and they are also related to proteins nifE and nifN, which are most probably involved in the iron-molybdenum cofactor biosynthesis .
We selected as signature patterns for this family of proteins two stretches of residues which are located in the N-terminal section and which each contain a conserved cysteine thought to be one of the ligands for the metal-sulfur clusters.Last update:
May 2004 / Text revised.
PROSITE methods (with tools and information) covered by this documentation:
|Title||Nitrogenases without molybdenum.|
|Source||Trends Biochem. Sci. 14:183-186(1989).|
|2||Authors||Aguilar O.M., Taormino J., Thony B., Ramseier T., Hennecke H., Szalay A.A.|
|Title||The nifEN genes participating in FeMo cofactor biosynthesis and genes encoding dinitrogenase are part of the same operon in Bradyrhizobium species.|
|Source||Mol. Gen. Genet. 224:413-420(1990).|