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Large nucleotide‐dependent movement of the N‐terminal domain of the ClpX chaperone
Author(s) -
Thibault Guillaume,
Tsitrin Yulia,
Davidson Toni,
Gribun Anna,
Houry Walid A
Publication year - 2006
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601223
Subject(s) - biology , chaperone (clinical) , escherichia coli proteins , nucleotide , terminal (telecommunication) , microbiology and biotechnology , biophysics , genetics , bacterial protein , gene , pathology , medicine , telecommunications , computer science
The ClpXP ATPase–protease complex is a major component of the protein quality control machinery in the cell. A ClpX subunit consists of an N‐terminal zinc binding domain (ZBD) and a C‐terminal AAA + domain. ClpX oligomerizes into a hexamer with the AAA + domains forming the base of the hexamer and the ZBDs extending out of the base. Here, we report that ClpX switches between a capture and a feeding conformation. ZBDs in ClpX undergo large nucleotide‐dependent block movement towards ClpP and into the AAA + ring. This motion is modulated by the ClpX cofactor, SspB. Evidence for this movement was initially obtained by the surprising observation that an N‐terminal extension on ClpX is clipped by bound ClpP in functional ClpXP complexes. Protease‐protection, crosslinking, and light scattering experiments further support these findings.