Understanding the Electronic Structure Basis for N₂ Binding to FeMoco: A Systematic Quantum Mechanics/Molecular Mechanics Investigation.

ABSTRACT: The FeMo cofactor (FeMoco) of Mo nitrogenase is responsible for reducing dinitrogen to ammonia, but it requires the addition of 3-4 e^-/H⁺ pairs before N₂ even binds. A binding site at the Fe2/Fe3/Fe6/Fe7 face of the cofactor has long been suggested based on mutation studies, with Fe2 or Fe6 nowadays being primarily discussed as possibilities. However, the nature of N₂ binding to the cofactor is enigmatic as the metal ions are coordinatively saturated in the resting state with no obvious binding site. Furthermore, the cofactor consists of high-spin Fe(II)/Fe(III) ions (antiferromagnetically coupled but also mixed-valence delocalized), which are not known to bind N₂. This suggests that an Fe binding site with a different molecular and el

SUBMITTER: Pang Y 

PROVIDER: S-EPMC10091479 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature