title: Structure of an endogenous yeast 26S proteasome reveals two major conformational states.
abstract: The eukaryotic proteasome mediates degradation of polyubiquitinated proteins. Here we report the single-particle cryoelectron microscopy (cryo-EM) structures of the endogenous 26S proteasome from Saccharomyces cerevisiae at 4.6- to 6.3-Å resolution. The fine features of the cryo-EM maps allow modeling of 18 subunits in the regulatory particle and 28 in the core particle. The proteasome exhibits two distinct conformational states, designated M1 and M2, which correspond to those reported previously for the proteasome purified in the presence of ATP-γS and ATP, respectively. These conformations also correspond to those of the proteasome in the presence and absence of exogenous substrate. Structure-guided biochemical analysis reveals enhanced deubiquitylating enzyme activity of Rpn11 upon assembly of the lid. Our structures serve as a molecular basis for mechanistic understanding of proteasome function.
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Bai
authors.initials: B
authors.lastname: Luan
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Xiuliang
authors.initials: X
authors.lastname: Huang
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Jianping
authors.initials: J
authors.lastname: Wu
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 10081, China;
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Mei
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Xue
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Chuangye
authors.initials: C
authors.lastname: Yan
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China;
authors.forename: Jiawei
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Finley
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; shi-lab@tsinghua.edu.cn wfeng@tsinghua.edu.cn.
authors.forename: Yigong
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; shi-lab@tsinghua.edu.cn wfeng@tsinghua.edu.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
mesh_terms: D020285:Cryoelectron Microscopy / Q000379:methods; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011487:Protein Conformation; D059748:Proteolysis; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D013379:Substrate Specificity
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease
keywords: cryo-EM; proteasome; protein degradation; structure