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-Structure paper
タイトル | The SspB adaptor drives structural changes in the AAA+ ClpXP protease during ssrA-tagged substrate delivery. |
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ジャーナル・号・ページ | Proc Natl Acad Sci U S A, Vol. 120, Issue 6, Page e2219044120, Year 2023 |
掲載日 | 2023年2月7日 |
著者 | Alireza Ghanbarpour / Xue Fei / Tania A Baker / Joseph H Davis / Robert T Sauer / |
PubMed 要旨 | Energy-dependent protein degradation by the AAA+ ClpXP protease helps maintain protein homeostasis in bacteria and eukaryotic organelles of bacterial origin. In and many other proteobacteria, the ...Energy-dependent protein degradation by the AAA+ ClpXP protease helps maintain protein homeostasis in bacteria and eukaryotic organelles of bacterial origin. In and many other proteobacteria, the SspB adaptor assists ClpXP in degrading ssrA-tagged polypeptides produced as a consequence of tmRNA-mediated ribosome rescue. By tethering these incomplete ssrA-tagged proteins to ClpXP, SspB facilitates their efficient degradation at low substrate concentrations. How this process occurs structurally is unknown. Here, we present a cryo-EM structure of the SspB adaptor bound to a GFP-ssrA substrate and to ClpXP. This structure provides evidence for simultaneous contacts of SspB and ClpX with the ssrA tag within the tethering complex, allowing direct substrate handoff concomitant with the initiation of substrate translocation. Furthermore, our structure reveals that binding of the substrate·adaptor complex induces unexpected conformational changes within the spiral structure of the AAA+ ClpX hexamer and its interaction with the ClpP tetradecamer. |
リンク | Proc Natl Acad Sci U S A / PubMed:36730206 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.7 Å |
構造データ | EMDB-28585, PDB-8et3: |
化合物 | ChemComp-AGS: ChemComp-ADP: |
由来 |
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キーワード | CHAPERONE / AAA+ protease / ClpXP / SspB adaptor / HYDROLASE |