Extended Data Fig. 2: Photocycle and sequence conservation.
a, Transient absorption spectra of TaHeR in E. coli membrane excited at λpump = 532 nm. b, Time evolutions of transient absorption changes at specific wavelengths of TaHeR in E. coli membrane. Each wavelength probes a different photochemical species: 409 nm for the M intermediate; 549 nm for the bleached dark state; and 605 nm for the K and O intermediates. ΔOD, change in optical density. c, Reconstructed absorption spectra obtained by the multi-exponential fitting for the time evolution of the transient absorption spectra shown in a. d, The photocycle of TaHeR, determined by the multi-exponential fitting for the time evolution of the transient absorption changes shown in a and b. In the measurement of the transient absorption spectra at t > 200 ms, a notch filter was placed in front of the ICCD detector, to minimize the scattered excitation pulse, and thus the absorption change could not be observed at λ = 523–540 nm in a and c (see details in Methods). These spectroscopy experiments were performed twice, and the representative data are shown. e, Maximum conserved residues and their conservation ratios in the HeR family members. The corresponding residues of TaHeR are also indicated with their residue numbers.
