Figure 4: Electron density for the metal containing cofactors.
From: Structure of a photosynthetic reaction centre determined by serial femtosecond crystallography
(a) mFobs−DFcalc residual electron density (green, contoured at 1.5σ) calculated with the two Mg atoms removed from the special pair. (b) mFobs−DFcalc residual electron density (green, contoured at 3.0σ) calculated with the Fe atom removed from haem 4. The 2mFobs−DFcalc electron density map (blue, contoured at 1.0σ) shows the electron density for the histidine side chains coordinating (a) the Mg atoms and (b) the iron.
