title: CryoEM structure of yeast cytoplasmic exosome complex.
abstract: The eukaryotic multi-subunit RNA exosome complex plays crucial roles in 3'-to-5' RNA processing and decay. Rrp6 and Ski7 are the major cofactors for the nuclear and cytoplasmic exosomes, respectively. In the cytoplasm, Ski7 helps the exosome to target mRNAs for degradation and turnover via a through-core pathway. However, the interaction between Ski7 and the exosome complex has remained unclear. The transaction of RNA substrates within the exosome is also elusive. In this work, we used single-particle cryo-electron microscopy to solve the structures of the Ski7-exosome complex in RNA-free and RNA-bound forms at resolutions of 4.2 Å and 5.8 Å, respectively. These structures reveal that the N-terminal domain of Ski7 adopts a structural arrangement and interacts with the exosome in a similar fashion to the C-terminal domain of nuclear Rrp6. Further structural analysis of exosomes with RNA substrates harboring 3' overhangs of different length suggests a switch mechanism of RNA-induced exosome activation in the through-core pathway of RNA processing.
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.|Joint Graduate Program of Peking-Tsinghua-National Institute of Biological Science, Tsinghua University, Beijing 100084, China.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Liu
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, 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: Chu-Ya
authors.initials: CY
authors.lastname: Niu
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wu
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Tan
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, 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: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, 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: Ming-Da
authors.initials: MD
authors.lastname: Ye
authors.affiliation: Joint Graduate Program of Peking-Tsinghua-National Institute of Biological Science, Tsinghua University, Beijing 100084, China.|MOE Key Laboratory of Bioinformatics, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: MOE Key Laboratory of Bioinformatics, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Wenwei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: The Multidiscipline Research Center, Institute of High Energy Physics of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhou
authors.affiliation: The Multidiscipline Research Center, Institute of High Energy Physics of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Quan-Sheng
authors.initials: QS
authors.lastname: Liu
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Junbiao
authors.initials: J
authors.lastname: Dai
authors.affiliation: MOE Key Laboratory of Bioinformatics, Tsinghua-Peking Joint Center for Life Sciences, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xuerui
authors.initials: X
authors.lastname: Yang
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Meng-Qiu
authors.initials: MQ
authors.lastname: Dong
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Niu
authors.initials: N
authors.lastname: Huang
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, 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: Hong-Wei
authors.initials: HW
authors.lastname: Wang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D020285:Cryoelectron Microscopy; D063326:Exosome Multienzyme Ribonuclease Complex / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055354:Exosomes / Q000737:chemistry / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D008958:Models, Molecular; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D000071376:RNA-Binding Motifs; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C118668:SKI7 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; D063326:Exosome Multienzyme Ribonuclease Complex; C112610:RRP6 protein, S cerevisiae