Spectroscopic Characterization of the Isolated Iron–Molybdenum Cofactor (FeMoco) Precursor from the Protein NifEN

Abstract

The fate of iron eight: The active site of Mo-nitrogenase is FeMoco. Previously, a FeMoco precursor was captured on NifEN, a scaffold protein for FeMoco biosynthesis. The FeMoco precursor is now isolated from the NifEN. The integrity of the precursor is shown by its full catalytic activity on incorporation into precursor-deficient NifEN. XAS/EXAFS analysis supports the eight-iron model of the precursor (see structure: Fe purple, S yellow).