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-Structure paper
タイトル | Mechanosensitive channel YnaI has lipid-bound extended sensor paddles. |
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ジャーナル・号・ページ | Commun Biol, Vol. 4, Issue 1, Page 602, Year 2021 |
掲載日 | 2021年5月20日 |
著者 | Wenxin Hu / Zhiming Wang / Hongjin Zheng / |
PubMed 要旨 | The general mechanism of bacterial mechanosensitive channels (MS) has been characterized by extensive studies on a small conductance channel MscS from Escherichia coli (E. coli). However, recent ...The general mechanism of bacterial mechanosensitive channels (MS) has been characterized by extensive studies on a small conductance channel MscS from Escherichia coli (E. coli). However, recent structural studies on the same channel have revealed controversial roles of various channel-bound lipids in channel gating. To better understand bacterial MscS-like channels, it is necessary to characterize homologs other than MscS. Here, we describe the structure of YnaI, one of the closest MscS homologs in E. coli, in its non-conducting state at 3.3 Å resolution determined by cryo electron microscopy. Our structure revealed the intact membrane sensor paddle domain in YnaI, which was stabilized by functionally important residues H43, Q46, Y50 and K93. In the pockets between sensor paddles, there were clear lipid densities that interact strongly with residues Q100 and R120. These lipids were a mixture of natural lipids but may be enriched in cardiolipin and phosphatidylserine. In addition, residues along the ion-conducting pathway and responsible for the heptameric assembly were discussed. Together with biochemical experiments and mutagenesis studies, our results provide strong support for the idea that the pocket lipids are functionally important for mechanosensitive channels. |
リンク | Commun Biol / PubMed:34017046 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.27 Å |
構造データ | EMDB-20862, PDB-6urt: |
化合物 | ChemComp-QGD: |
由来 |
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キーワード | MEMBRANE PROTEIN / mechanosensitive channel / Phosphoserine lipid / complete paddle |