Fig. 6
From: Red-shifting mutation of light-driven sodium-pump rhodopsin

Quantum mechanics/molecular mechanics structures around retinal chromophore in KR2 wildtype (WT) and mutants. Comparison between retinal chromophores and mutated residues 219 and 254 in a KR2 WT, b P219G, c P219T, d S254A and e P219T/S254A mutants. For mutants are also shown, in transparent representation, the retinal chromophore and 219 and 254 residues of KR2 WT