Extended Data Fig. 2: mFobs − DFcalc electron density map near the OEC region in the 3F(500 µs) time point.
From: Structural evidence for intermediates during O2 formation in photosystem II
The map is shown at a contour level of 2.5σ (in yellow). Electron density is observed at this level in-between W3 and W4 (see red arrow), possibly indicating a transient water motion that was also corroborated by the overlap of the omit map densities. For comparison, the individual omit maps of W3 and W4 are also overlaid at 2.5, 3 and 4σ (color scheme same as in Fig. 2 in main text). Stronger electron density is also observed around W1/D61 possibly related to motion involving a proton transfer as discussed in the main text related to Fig. 2. Electron density around the O1 is possibly related to changes observed in the W26-W30 (referred to as the ‘water wheel’ region) in this time point (discussed in main text related to Fig. 4).
