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-Structure paper
Title | Structures of the ATP-fueled ClpXP proteolytic machine bound to protein substrate. |
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Journal, issue, pages | Elife, Vol. 9, Year 2020 |
Publish date | Feb 28, 2020 |
Authors | Xue Fei / Tristan A Bell / Simon Jenni / Benjamin M Stinson / Tania A Baker / Stephen C Harrison / Robert T Sauer / |
PubMed Abstract | ClpXP is an ATP-dependent protease in which the ClpX AAA+ motor binds, unfolds, and translocates specific protein substrates into the degradation chamber of ClpP. We present cryo-EM studies of the ...ClpXP is an ATP-dependent protease in which the ClpX AAA+ motor binds, unfolds, and translocates specific protein substrates into the degradation chamber of ClpP. We present cryo-EM studies of the enzyme that show how asymmetric hexameric rings of ClpX bind symmetric heptameric rings of ClpP and interact with protein substrates. Subunits in the ClpX hexamer assume a spiral conformation and interact with two-residue segments of substrate in the axial channel, as observed for other AAA+ proteases and protein-remodeling machines. Strictly sequential models of ATP hydrolysis and a power stroke that moves two residues of the substrate per translocation step have been inferred from these structural features for other AAA+ unfoldases, but biochemical and single-molecule biophysical studies indicate that ClpXP operates by a probabilistic mechanism in which five to eight residues are translocated for each ATP hydrolyzed. We propose structure-based models that could account for the functional results. |
External links | Elife / PubMed:32108573 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.19 - 4.28 Å |
Structure data | EMDB-20406, PDB-6po1: EMDB-20408, PDB-6po3: EMDB-20412, PDB-6pod: EMDB-20418, PDB-6pos: EMDB-20419, PDB-6pp5: EMDB-20420, PDB-6pp6: EMDB-20421, PDB-6pp7: EMDB-20422, PDB-6pp8: EMDB-20434, PDB-6ppe: |
Chemicals | ChemComp-AGS: ChemComp-ADP: ChemComp-HOH: |
Source |
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Keywords | CHAPERONE / Protein degradation / AAA+ protease complex |