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Published on: October 18, 2019
Structure of precursor-bound NifEN: a nitrogenase FeMo cofactor maturase/insertase
Jens T Kaiser1, Yilin Hu, Jared A Wiig
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Mail Code 114-96, Pasadena, CA 91125, USA.
None:
NifEN plays an essential role in the biosynthesis of the nitrogenase iron-molybdenum (FeMo) cofactor (M cluster). It is an α(2)β(2) tetramer that is homologous to the catalytic molybdenum-iron (MoFe) protein (NifDK) component of nitrogenase. NifEN serves as a scaffold for the conversion of an iron-only precursor to a matured form of the M cluster before delivering the latter to its target location within NifDK. Here, we present the structure of the precursor-bound NifEN of Azotobacter vinelandii at 2.6 angstrom resolution. From a structural comparison of NifEN with des-M-cluster NifDK and holo NifDK, we propose similar pathways of cluster insertion for the homologous NifEN and NifDK proteins.
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