Figure 5
From: X-ray structure analysis of bacteriorhodopsin at 1.3 Å resolution

Multi-conformations around the proton release group. (a) The 2Fobs − Fcalc map is shown at contour levels of 2σ (gray) and 4σ (dark gray). (b) Hydrogen bonds shorter than 3.2 Å for the major conformation are represented as black dotted lines. (c) Hydrogen bonds for the minor conformation are represented as gray dotted lines. (d) Comparison of the conformations of Glu194 and Glu204 with those in 1IW6 (blue). (e) Comparison with 1C3W (pink).