Extended Data Fig. 3: Light-induced structural changes in cpLOV2 revealed by high-resolution NMR.
From: Circularly permuted LOV2 as a modular photoswitch for optogenetic engineering
a, The secondary structure of cpLOV2 in the dark state was predicted based on the backbone chemical shifts. Probability values > 0.7 or < −0.7 (horizontal dashed lines) indicates significant changes from random coil. Shown on the top is the secondary structure of LOV2. b, Schematic (left panel) and a representative photograph (right panel) illustrating the installation of an external LED to enable acquisition of the NMR spectrum for cpLOV2 in its blue light-illuminated state. c, 2D 1H-15N HSQC spectra of cpLOV2 in the dark (black) and lit states (red). The conformation of cpLOV2 was greatly altered after blue light illumination as reflected by the massive changes in chemical shifts of multiple peaks. d, Overlaid 2D 1H-15N HSQC spectra of LOV2 (black) and cpLOV2 (red) in the dark (left) or lit states (right). The conformation of cpLOV2 was very similar to LOV2 in the lit state. e, Surface representation of cpLOV2. Circle, new surface areas (left, 3.7 nm2; right, 7.4 nm2) that can be utilized to cage an effector ___domain fused to the N terminus of cpLOV2. The new N- and C- termini are shown in red and blue, respectively.
