A, X-ray structure of the resting-state BioB with DTB and SAM bound (PDB: 1r30), adapted from reference 6. B, Structural model (model A) derived from quantum chemical modeling using broken-symmetry DFT. C, The hyperfine coupling tensors of the multiple nuclei in the intermediate. The uncertainty of the experimental extracted hyperfine parameters is ± 0.01 MHz. Tnon-loc is computed using Randall’s model33 with spin-projection factors calculated from the structure shown in B, with KA = 2.087 and KB = −1.087. Both Exp-Tdip and DFT-Tdip include small contributions of Tloc (except for 1H and 2H, see
Materials and Methods for details). The distance r in the rightmost column is corresponding to the nucleus to the nearer iron center (ferric iron for three protons and ferrous iron for the other nuclei) in model A.