Fig. 8: Anomalous difference Fourier synthesis computed for the [Fe-Ni-Se] hydrogenase from Desulfomicrobium baculatum. The synthesis was computed with all data between 8.0 Å and 2.15 Å, using model phases; data were collected on beamline D2AM (a French CRG beamline at the ESRF) at a wavelength of 0.98 Å. The three [4Fe-4S] clusters forming the electron transport chain, the bi-nuclear Fe-Ni active centre, and the additional Fe atom are all clearly visible.