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-Structure paper
タイトル | Structural basis of ClpXP recognition and unfolding of ssrA-tagged substrates. |
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ジャーナル・号・ページ | Elife, Vol. 9, Year 2020 |
掲載日 | 2020年10月22日 |
著者 | Xue Fei / Tristan A Bell / Sarah R Barkow / Tania A Baker / Robert T Sauer / |
PubMed 要旨 | When ribosomes fail to complete normal translation, all cells have mechanisms to ensure degradation of the resulting partial proteins to safeguard proteome integrity. In and other eubacteria, the ...When ribosomes fail to complete normal translation, all cells have mechanisms to ensure degradation of the resulting partial proteins to safeguard proteome integrity. In and other eubacteria, the tmRNA system rescues stalled ribosomes and adds an ssrA tag or degron to the C-terminus of the incomplete protein, which directs degradation by the AAA+ ClpXP protease. Here, we present cryo-EM structures of ClpXP bound to the ssrA degron. C-terminal residues of the ssrA degron initially bind in the top of an otherwise closed ClpX axial channel and subsequently move deeper into an open channel. For short-degron protein substrates, we show that unfolding can occur directly from the initial closed-channel complex. For longer degron substrates, our studies illuminate how ClpXP transitions from specific recognition into a nonspecific unfolding and translocation machine. Many AAA+ proteases and protein-remodeling motors are likely to employ similar multistep recognition and engagement strategies. |
リンク | Elife / PubMed:33089779 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.88 - 3.16 Å |
構造データ | EMDB-21875, PDB-6wr2: EMDB-21882, PDB-6wrf: EMDB-21892, PDB-6wsg: |
化合物 | ChemComp-HOH: ChemComp-AGS: ChemComp-MG: ChemComp-ADP: |
由来 |
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キーワード | CHAPERONE (シャペロン) / Protein degradation (タンパク質分解) / AAA+ protease complex |