Nucleotide-dependent conformational changes in a protease-associated ATPase HsIU.
Structure
; 9(11): 1107-16, 2001 Nov.
Article
in En
| MEDLINE
| ID: mdl-11709174
ABSTRACT
BACKGROUND:
The bacterial heat shock locus ATPase HslU is an AAA(+) protein that has structures known in many nucleotide-free and -bound states. Nucleotide is required for the formation of the biologically active HslU hexameric assembly. The hexameric HslU ATPase binds the dodecameric HslV peptidase and forms an ATP-dependent HslVU protease.RESULTS:
We have characterized four distinct HslU conformational states, going sequentially from open to closed the empty, SO(4), ATP, and ADP states. The nucleotide binds at a cleft formed by an alpha/beta domain and an alpha-helical domain in HslU. The four HslU states differ by a rotation of the alpha-helical domain. This classification leads to a correction of nucleotide identity in one structure and reveals the ATP hydrolysis-dependent structural changes in the HslVU complex, including a ring rotation and a conformational change of the HslU C terminus. This leads to an amended protein unfolding-coupled translocation mechanism.CONCLUSIONS:
The observed nucleotide-dependent conformational changes in HslU and their governing principles provide a framework for the mechanistic understanding of other AAA(+) proteins.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Endopeptidases
/
Serine Endopeptidases
/
Adenine Nucleotides
/
Adenosine Triphosphatases
/
Heat-Shock Proteins
Type of study:
Risk_factors_studies
Language:
En
Journal:
Structure
Journal subject:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
BIOTECNOLOGIA
Year:
2001
Type:
Article
Affiliation country:
United States