WikiGenes - nifB - FeMo cofactor biosynthesis protein
Yukl ET and Wilmot CM (2012) Cofactor biosynthesis through protein post‐translational modification. Current Opinion in Chemical Biology 16: 54–59.
Cofactor (biochemistry) - Wikipedia
Davidson VL and Wilmot CM (2013) Posttranslational biosynthesis of the protein‐derived cofactor tryptophan tryptophylquinone. Annual Review of Biochemistry 82: 531–550.
The nifB gene has been long recognized as crucial for nitrogen fixation because nifB participates in an early synthetic step that is common to the biosyntheses of FeMo-cofactor. NifB proteins contain the signature motif of SAM radical enzymes (CxxxCxxC) at the N-terminal region, they also show the presence of nine conserved cysteine residues that could potentially coordinate additional [Fe–S] clusters and a C-terminal region that is conserved among proteins able to bind FeMo-co or NifB-co. However, very little appears to be known about their function and mechanism.