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DOI	10.1073/pnas.2016328118
	Crystal structure of schizorhodopsin reveals mechanism of inward proton pumping
	Higuchi A.; Shihoya W.; Konno M.; Ikuta T.; Kandori H.; Inoue K.; Nureki O.
发表日期	2021
ISSN	00278424
卷号	118 期号:14
英文摘要	Schizorhodopsins (SzRs), a new rhodopsin family identified in Asgard archaea, are phylogenetically located at an intermediate position between type-1 microbial rhodopsins and heliorhodopsins. SzRs work as light-driven inward H+ pumps as xenorhodopsins in bacteria. Although E81 plays an essential role in inward H+ release, the H+ is not metastably trapped in such a putative H+ acceptor, unlike the other H+ pumps. It remains elusive why SzR exhibits different kinetic behaviors in H+ release. Here, we report the crystal structure of SzR AM_5_00977 at 2.1 Å resolution. The SzR structure superimposes well on that of bacteriorhodopsin rather than heliorhodopsin, suggesting that SzRs are classified with type-1 rhodopsins. The structure-based mutagenesis study demonstrated that the residues N100 and V103 around the β-ionone ring are essential for color tuning in SzRs. The cytoplasmic parts of transmembrane helices 2, 6, and 7 are shorter than those in the other microbial rhodopsins, and thus E81 is located near the cytosol and easily exposed to the solvent by light-induced structural change. We propose a model of untrapped inward H+ release; H+ is released through the water-mediated transport network from the retinal Schiff base to the cytosol by the side of E81. Moreover, most residues on the H+ transport pathway are not conserved between SzRs and xenorhodopsins, suggesting that they have entirely different inward H+ release mechanisms. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Proton pump; Rhodopsin; X-ray crystallography
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179983
作者单位	Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan; The Institute for Solid State Physics, The University of Tokyo, Kashiwa, 277-8581, Japan; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho, Saitama, Kawaguchi, 332-0012, Japan; Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa, Nagoya, 466-8555, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa, Nagoya, 466-8555, Japan
推荐引用方式 GB/T 7714	Higuchi A.,Shihoya W.,Konno M.,et al. Crystal structure of schizorhodopsin reveals mechanism of inward proton pumping[J],2021,118(14).
APA	Higuchi A..,Shihoya W..,Konno M..,Ikuta T..,Kandori H..,...&Nureki O..(2021).Crystal structure of schizorhodopsin reveals mechanism of inward proton pumping.Proceedings of the National Academy of Sciences of the United States of America,118(14).
MLA	Higuchi A.,et al."Crystal structure of schizorhodopsin reveals mechanism of inward proton pumping".Proceedings of the National Academy of Sciences of the United States of America 118.14(2021).