The nifY product of Klebsiella pneumoniae is associated with apodinitrogenase and dissociates upon activation with the iron-molybdenum cofactor

The nitrogen enzyme comprises two components, of which component I catalyzes the reduction of N2 and other substrates and component II transfers electrons to dinitrogenase. Component I employs iron-molybdenum cofactor as an activizer, and is synthesized by the nif gene products. Apodinitrogenase is an oligomer that is comprised of an additional protein absent in the active dinitrogenase tetramer, and it lacks the iron-molybdenum cofactor at its active site. The protein in Klebsiella pneumoniae is a product of the nifY gene.