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Mechanism of Gate Opening in the 20S Proteasome by the Proteasomal ATPases
- Source :
-
Molecular Cell . May2008, Vol. 30 Issue 3, p360-368. 9p. - Publication Year :
- 2008
-
Abstract
- Summary: Substrates enter the cylindrical 20S proteasome through a gated channel that is regulated by the ATPases in the 19S regulatory particle in eukaryotes or the homologous PAN ATPase complex in archaea. These ATPases contain a conserved C-terminal hydrophobic-tyrosine-X (HbYX) motif that triggers gate opening upon ATP binding. Using cryo-electron microscopy, we identified the sites in the archaeal 20S where PAN''s C-terminal residues bind and determined the structures of the gate in its closed and open forms. Peptides containing the HbYX motif bind to 20S in the pockets between neighboring α subunits where they interact with conserved residues required for gate opening. This interaction induces a rotation in the α subunits and displacement of a reverse-turn loop that stabilizes the open-gate conformation. This mechanism differs from that of PA26/28, which lacks the HbYX motif and does not cause α subunit rotation. These findings demonstrated how the ATPases'' C termini function to facilitate substrate entry. [Copyright &y& Elsevier]
- Subjects :
- *MICROSCOPY
*OPTICS
*CHEMICAL microscopy
*CONFOCAL microscopy
Subjects
Details
- Language :
- English
- ISSN :
- 10972765
- Volume :
- 30
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Molecular Cell
- Publication Type :
- Academic Journal
- Accession number :
- 32053885
- Full Text :
- https://doi.org/10.1016/j.molcel.2008.03.004