Nitrogenase component 1, alpha chain (IPR010143)

Short name: Nase_comp1_asu

Overlapping homologous superfamilies


Family relationships


This entry represents all three varieties (Fe-Fe, Mo-Fe and V-Fe) of the component I alpha chain of nitrogenase.

Nitrogenase (EC: [PMID: 2672439] 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-sulphur protein, while component 1 which contains the active site for the reduction of nitrogen to ammonia exists in three different forms: the molybdenum-iron containing protein (MoFe) is a hetero-tetramer consisting of two pairs of alpha (nifD) and beta (nifK) subunits; the vanadium-iron containing protein (VFe) is a hexamer of two pairs each of alpha (vnfD), beta (vnfK), and delta (vnfG) subunits; the third form seems to only contain iron and is a hexamer composed of alpha (anfD), beta (anfK), and delta (anfG) subunits. The alpha and beta 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 [PMID: 2266945].

GO terms

Biological Process

GO:0009399 nitrogen fixation
GO:0055114 oxidation-reduction process

Molecular Function

GO:0051536 iron-sulfur cluster binding
GO:0016163 nitrogenase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.