7qve
Spinach 20S proteasome
Structural highlights
FunctionPSA3_SPIOL The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. Publication Abstract from PubMedTargeted proteolysis is a hallmark of life. It is especially important in long-lived cells that can be found in higher eukaryotes, like plants. This task is mainly fulfilled by the ubiquitin-proteasome system. Thus, proteolysis by the 26S proteasome is vital to development, immunity, and cell division. Although the yeast and animal proteasomes are well characterized, there is only limited information on the plant proteasome. We determined the first plant 26S proteasome structure from Spinacia oleracea by single-particle electron cryogenic microscopy at an overall resolution of 3.3 A. We found an almost identical overall architecture of the spinach proteasome compared with the known structures from mammals and yeast. Nevertheless, we noticed a structural difference in the proteolytic active beta1 subunit. Furthermore, we uncovered an unseen compression state by characterizing the proteasome's conformational landscape. We suspect that this new conformation of the 20S core protease, in correlation with a partial opening of the unoccupied gate, may contribute to peptide release after proteolysis. Our data provide a structural basis for the plant proteasome, which is crucial for further studies. Cryo-EM structure of the plant 26S proteasome.,Kandolf S, Grishkovskaya I, Belacic K, Bolhuis DL, Amann S, Foster B, Imre R, Mechtler K, Schleiffer A, Tagare HD, Zhong ED, Meinhart A, Brown NG, Haselbach D Plant Commun. 2022 May 9;3(3):100310. doi: 10.1016/j.xplc.2022.100310. Epub 2022 , Mar 11. PMID:35576154[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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