Linked from
The 11 pages that link to Nitrogenase, each with the reason it gives.
Nitrogen fixationRelated: It catalyzes biological fixation and must be protected from oxygen.
Root noduleRelated: It carries out nitrogen fixation inside nodule bacteria.
AzollaBroader topic: The cyanobacterial partner uses this oxygen-sensitive enzyme to fix nitrogen.
AnabaenaRelated: Heterocysts protect this enzyme complex so Anabaena can fix nitrogen.