Fig. 4.
The characteristics of C-terminal truncated MosOpn3-based pigment bearing 13-cis retinal. (A) Absorption spectra and chromophore configurations of the MosOpn3ΔC-based pigments constituted by incubation with 11-cis (black curve and trace), all-trans (blue curve and trace), 9-cis (green curve and trace), and 13-cis (red curve and trace) retinals, respectively. The absorption spectrum of the MosOpn3ΔC-based pigment constituted by 13-cis retinal (red curve) was calculated to exclude the contribution of the contaminated 11-cis retinal-bearing MosOpn3ΔC-based pigment based on the chromophore configuration (red trace) (Fig. S5). Note that the MosOpn3ΔC-based pigment constituted by incubation with all-trans retinal selectively binds 13-cis retinal, which was thermally generated from the all-trans form. (B) The Gi and Go activation abilities of the 13-cis retinal-bearing MosOpn3ΔC-based pigment. The open and filled circles indicate G protein activation in the presence of the irradiated and nonirradiated pigments, respectively.