Nitrogenase consists of alpha (NifD) and beta (NifK) subunits of the molybdenum-iron protein and an ATP-binding iron-sulfur protein (NifH). This model describes a large clade of NifD proteins, but excludes a lineage that contains putative NifD and NifD homologs from species with vanadium-dependent nitrogenases. [Central intermediary metabolism, Nitrogen fixation]
Jiyao W et al.(2023). "The conserved domain database in 2023.",