6WSG

ClpX-ClpP complex bound to ssrA-tagged GFP, intermediate complex

Summary for 6WSG

• Entry DOI: 10.2210/pdb6wsg/pdb
• Related: 6WR2 6WRF
• EMDB information: 21875 21882 21892
• Descriptor: ATP-dependent Clp protease ATP-binding subunit ClpX, ATP-dependent Clp protease proteolytic subunit, Green fluorescent protein, + ssrA tag, ... (6 entities in total)
• Functional Keywords: protein degradation, aaa+ protease complex, chaperone
• Biological source: Escherichia coli; More
• Total number of polymer chains: 14
• Total formula weight: 451472.15

Authors

Fei, X.,Sauer, R.T. (deposition date: 2020-04-30, release date: 2020-11-04, Last modification date: 2024-03-06)

Primary citation

Fei, X.,Bell, T.A.,Barkow, S.R.,Baker, T.A.,Sauer, R.T.
Structural basis of ClpXP recognition and unfolding of ssrA-tagged substrates.
Elife, 9:-, 2020

PubMed Abstract: 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.

PubMed: 33089779
DOI: 10.7554/eLife.61496

Experimental method

ELECTRON MICROSCOPY (3.16 Å)