Light-Induced Conformational Alterations in Heliorhodopsin Triggered by the Retinal Excited State.

ABSTRACT: Heliorhodopsins are a recently discovered diverse retinal protein family with an inverted topology of the opsin where the retinal protonated Schiff base proton is facing the cell cytoplasmic side in contrast to type 1 rhodopsins. To explore whether light-induced retinal double-bond isomerization is a prerequisite for triggering protein conformational alterations, we utilized the retinal oxime formation reaction and thermal denaturation of a native heliorhodopsin of Thermoplasmatales archaeon SG8-52-1 (TaHeR) as well as a trans-locked retinal analogue (TaHeR_L) in which the critical C₁₃═C₁₄ double-bond isomerization is prevented. We found that both reactions are light-accelerated not only in the native but also in the "locked" pigment despite la

SUBMITTER: Das I 

PROVIDER: S-EPMC8389987 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature