An atomic model AAA-ATPase/20S core particle sub-complex of the 26S proteasome.
The 26S proteasome is the most downstream element of the ubiquitin-proteasome pathway of protein degradation. It is composed of the 20S core particle (CP) and the 19S regulatory particle (RP). The RP consists of 6 AAA-ATPases and at least 13 non-ATPase subunits. Based on a cryo-EM map of the 26S proteasome, structures of homologs, and physical protein-protein interactions we derive an atomic model of the AAA-ATPase-CP sub-complex. The ATPase order in our model (Rpt1/Rpt2/Rpt6/Rpt3/Rpt4/Rpt5) is in excellent agreement with the recently identified base-precursor complexes formed during the assembly of the RP. Furthermore, the atomic CP-AAA-ATPase model suggests that the assembly chaperone Nas6 facilitates CP-RP association by enhancing the shape complementarity between Rpt3 and its binding CP alpha subunits partners.
Förster
Friedrich
F
Department of Structural Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany.
Lasker
Keren
K
Beck
Florian
F
Nickell
Stephan
S
Sali
Andrej
A
Baumeister
Wolfgang
W
D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000818:Animals; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D004331:Drosophila melanogaster / Q000201:enzymology*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry*; D020836:Protein Structure, Quaternary
D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000251:Adenosine Triphosphatases