Fig. 3: Molecular model and spectral features of NeoR mutants.

a Homology model of the NeoR retinal-binding pocket, with the amino acids targeted by mutagenesis drawn as sticks. b Absorption spectra of NeoR mutants; spectra are normalized to the respective UV-form. c Spectral features of NeoR mutants; sw, bimodal switchable; dp, depronotated chromophore; ФF, fluorescence quantum yield (in %). d Emission spectra (at 650 nm), and e excitation spectra (at 720 nm) of wild-type (WT) NeoR and NeoR mutants.