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Mutations conferring SO42- pumping ability on the cyanobacterial anion pump rhodopsin and the resultant unique features of the mutant
Title: | Mutations conferring SO42- pumping ability on the cyanobacterial anion pump rhodopsin and the resultant unique features of the mutant |
Authors: | Doi, Yuhei Browse this author | Watanabe, Jo Browse this author | Nii, Ryota Browse this author | Tsukamoto, Takashi Browse this author | Demura, Makoto Browse this author | Sudo, Yuki Browse this author | Kikukawa, Takashi Browse this author →KAKEN DB |
Issue Date: | 30-Sep-2022 |
Publisher: | Nature Portfolio |
Journal Title: | Scientific reports |
Volume: | 12 |
Issue: | 1 |
Start Page: | 16422 |
Publisher DOI: | 10.1038/s41598-022-20784-6 |
Abstract: | Membrane transport proteins can be divided into two types: those that bind substrates in a resting state and those that do not. In this study, we demonstrate that these types can be converted by mutations through a study of two cyanobacterial anion-pumping rhodopsins, Mastigocladopsis repens halorhodopsin (MrHR) and Synechocystis halorhodopsin (SyHR). Anion pump rhodopsins, including MrHR and SyHR, initially bind substrate anions to the protein center and transport them upon illumination. MrHR transports only smaller halide ions, Cl- and Br-, but SyHR also transports SO42-, despite the close sequence similarity to MrHR. We sought a determinant that could confer SO42- pumping ability on MrHR and found that the removal of a negative charge at the anion entrance is a prerequisite for SO42- transport by MrHR. Consistently, the reverse mutation in SyHR significantly weakened SO42- pump activity. Notably, the MrHR and SyHR mutants did not show SO42- induced absorption spectral shifts or changes in the photoreactions, suggesting no bindings of SO42- in their initial states or the bindings to the sites far from the protein centers. In other words, unlike wild-type SyHR, these mutants take up SO42- into their centers after illumination and release it before the ends of the photoreactions. |
Type: | article |
URI: | http://hdl.handle.net/2115/87086 |
Appears in Collections: | 生命科学院・先端生命科学研究院 (Graduate School of Life Science / Faculty of Advanced Life Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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