5K, 7T MCD spectra of wt-FIH(black), D201GCl(red), D201G(blue), D201E(green) and D201A(purple). A) FeII-loaded resting sites, B) FeII/αKG sites and C) FeII/αKG/CAD ternary sites. In A, B and C, the Gaussianresolved band energies and Δ5E splittings are summarized in Table 1. The arrows indicate the energies at which VTVH data were collected for each sample.