Structural Insights into the Regulatory Particle of the Proteasome from Methanocaldococcus jannaschii.Zhang, F., Hu, M., Tian, G., Zhang, P., Finley, D., Jeffrey, P.D., Shi, Y.
(2009) Mol Cell 34: 473-484
- PubMed: 19481527
- DOI: https://doi.org/10.1016/j.molcel.2009.04.021
- Primary Citation of Related Structures:
3H43, 3H4M, 3H4P
- PubMed Abstract:
Eukaryotic proteasome consists of a core particle (CP), which degrades unfolded protein, and a regulatory particle (RP), which is responsible for recognition, ATP-dependent unfolding, and translocation of polyubiquitinated substrate protein. In the archaea Methanocaldococcus jannaschii, the RP is a homohexameric complex of proteasome-activating nucleotidase (PAN). Here, we report the crystal structures of essential elements of the archaeal proteasome: the CP, the ATPase domain of PAN, and a distal subcomplex that is likely the first to encounter substrate. The distal subcomplex contains a coiled-coil segment and an OB-fold domain, both of which appear to be conserved in the eukaryotic proteasome. The OB domains of PAN form a hexameric ring with a 13 A pore, which likely constitutes the outermost constriction of the substrate translocation channel. These studies reveal structural codes and architecture of the complete proteasome, identify potential substrate-binding sites, and uncover unexpected asymmetry in the RP of archaea and eukaryotes.
Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA.