Heliorhodopsin Helps Photolyase to Enhance the DNA Repair Capacity

Abstract

This study reports a function for Heliorhodopsin working as a regulatory helper rhodopsin that with CPDII photolyase to broaden the spectrum and upregulating the DNA repair activity. Our results suggested that heliorhodopsin directly controls photolyase activity and coevolves to broaden the DNA repair capacity by protein-protein interaction.

Specific zinc binding to heliorhodopsin

“…In addition, the regulation of glutamine synthetase and photolyase by HeRs from the Actinobacteria bacterium and Trichococcus flocculiformis, respectively, was recently reported. 36,37 Further experimental and theoretical studies will lead to a better understanding of the structure and function of HeRs, deepening our knowledge of rhodopsins. 1,38…”

Time-resolved detection of light-induced conformational changes of heliorhodopsin

“…11,12 Furthermore, the lightinduced conformational change on the cytoplasmic side is relevant for the function of rhodopsins in many cases. 9,10,30 Hence, we speculate that this helix is involved in the photoreaction of HeR. For examining conformation change in this region, we prepared a mutant TaHeR Y93G and investigated the reaction, because Y93 locates in the ICL1 helix to be a part of a hydrogen bonding network that extending from the retinal (Fig.…”

“…6 In 2018, the third class of rhodopsin, heliorhodopsin (HeR), was discovered by the functional metagenome analysis. 7 Although the biological function of most HeRs is not known except for a few members, [8][9][10] they exhibit a characteristic inverted orientation relative to the canonical microbial and animal rhodopsins with the N-and C-termini facing the intracellular and extracellular sides, respectively. 7,11 HeR 48C12 and HeR from Thermoplasmatales archaeon SG8-52-1 (TaHeR) were revealed to form dimers by X-ray crystallography in which protomers are bridged to each other by their long extracellular loops between TM1 and 2 (Fig.…”

pH-Dependent Binding and Releasing Mechanism of Acetate in the Inner Water Cavity of Heliorhodopsin

“…1 While its function is not yet fully understood, it has been proposed to serve as a photosensor, 1−3 transporter, 4,5 proton channel, 6 and regulatory rhodopsin for glutamine synthetase 7 or photolyase. 8 The crystal structure of bacterial heliorhodopsin 48C12 shows that the retinal Schiff base and the counterion Glu107 exist in the inner water cavity, which connects with the intracellular bulk surface 1 (Figure 1). Photoisomerization of the all-trans retinal Schiff base leads to the release of a proton via Glu107 and water molecules toward His80/His23, 1,9−12 resulting in internal proton transfer 1,13 and conformational changes in the protein.…”

“…Heliorhodopsin is a recently discovered retinal protein that distinguishes itself from other microbial rhodopsins by having its N- and C-terminals located on the intracellular and extracellular sides, respectively . While its function is not yet fully understood, it has been proposed to serve as a photosensor, − transporter, , proton channel, and regulatory rhodopsin for glutamine synthetase or photolyase …”