Supplementary Information 2

1) Figure S1. Fe K-­‐edge XANES region for ferric and compound I forms of CPO and CYP119A1. (Page 2) 2) Figure S2. Pre-­‐edge data for P450-­‐I and CPO-­‐I. (Page 3) 3) Figure S3. EXAFS of ferric P450. (Page 4) 4) Figure S4. Compound I Mössbauer spectra at 4.2 K. (Page 5) 5) Figure S5. EXAFS and Fourier transforms for CYP119A2-­‐I and CYP158A2*-­‐I. (Page 6) 6) Figure S6. Variable temperature Mössbauer data and fits for CYP119A1-­‐I and CPO-­‐I. (Page 7) 7) Figure S7. Variable temperature Mössbauer data for ferric CYP119A1. (Page 8) 8) Table S1. Ground-­‐state (S=1/2) Mössbauer parameters used to simulate spectra presented in Figure 3 and S6. (Page 9) 9) Table S2. Temperature dependent relaxation parameters used for simulating Mössbauer spectra presented in Figure 3 and S6. (Page 9) 10) Table S3. Best fits for ferric P450 EXAFS data. (Page 10) 11) Optimized coordinates for calculations. (Page 11)