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Docking of the Proteasomal ATPases' Carboxyl Termini in the 20S Proteasome's α Ring Opens the Gate for Substrate Entry
- Source :
-
Molecular Cell . Sep2007, Vol. 27 Issue 5, p731-744. 14p. - Publication Year :
- 2007
-
Abstract
- Summary: The 20S proteasome functions in protein degradation in eukaryotes together with the 19S ATPases or in archaea with the homologous PAN ATPase complex. These ATPases contain a conserved C-terminal hydrophobic-tyrosine-X motif (HbYX). We show that these residues are essential for PAN to associate with the 20S and open its gated channel for substrate entry. Upon ATP binding, these C-terminal residues bind to pockets between the 20S''s α subunits. Seven-residue or longer peptides from PAN''s C terminus containing the HbYX motif also bind to these sites and induce gate opening in the 20S. Gate opening could be induced by C-terminal peptides from the 19S ATPase subunits, Rpt2, and Rpt5, but not by ones from PA28/26, which lack the HbYX motif and cause gate opening by distinct mechanisms. C-terminal residues in the 19S ATPases were also shown to be critical for gating and stability of 26S proteasomes. Thus, the C termini of the proteasomal ATPases function like a “key in a lock” to induce gate opening and allow substrate entry. [Copyright &y& Elsevier]
- Subjects :
- *HYDROPHOBIC surfaces
*ADENOSINE triphosphatase
*PEPTIDES
*PROTEASE inhibitors
Subjects
Details
- Language :
- English
- ISSN :
- 10972765
- Volume :
- 27
- Issue :
- 5
- Database :
- Academic Search Index
- Journal :
- Molecular Cell
- Publication Type :
- Academic Journal
- Accession number :
- 26414975
- Full Text :
- https://doi.org/10.1016/j.molcel.2007.06.033