Fig. 1. (A) The ONIOM partition of GFP adopted in this study. The ONIOM model (ball and stick representation) includes the chromophore completed by the Ser65 side chain, the hydrogen bonded crystallographic water molecule and the side chains of Ser205 and Glu222. (B) The residues and hydrogen bond network involved in the ESPT reaction in the ball-and-stick representation. The His148 residue, involved in a hydrogen bond with the chromophore phenolic ring, is also included. His148 is described at the MM theory level in this paper, so it is shown in the tube representation.
