Fig. 4. Structures of the F₂Y224–FtmOx1 mutant. (a). Superimposition of the F₂Y224–FtmOx1·Fe^II (PDB entry 9J1I) structure with FtmOx1·Fe^II (PDB entry 4Y5T) and FtmOx1·Fe^II·αKG (PDB entry 4Y5S) structures. The F₂Y224–FtmOx1·Fe^II structure is shown in yellow. The FtmOx1·Fe^II structure is shown in grey. The FtmOx1·Fe^II·αKG structure is shown in pink. (b). The omit map of the F₂Y224–FtmOx1 metallo-center (2mFo-DFc) at 1σ contour. The map was generated by phenix using simple refinement after omitting each region. The electron density around each compound is shown in grey mesh. The residues coordinating with the metallo-center are shown as sticks. The coordination of iron is represented by dashed lines. (c). Superimposition of F₂Y224–FtmOx1·Fe^II metallo-center (PDB entry 9J1I) with FtmOx1·Fe^II (PDB entry 4Y5T). The F₂Y224–FtmOx1 metallo-center is shown in green. The FtmOx1·Fe^II metallo-center is shown in grey. (d). F₂Y224–FtmOx1·Co^II·αKG binary (PDB entry 9J1H) complex. The omit map of the metallo-center and αKG (2mFo-DFc) at 1σ contour. The electron density around each compound is shown in grey mesh. The residues within 4 Å around the αKG are shown as stick. The distances between Y224F₂Y and the αKG and the metallo-center are highlighted with black dashed lines.