3.3 Å Cryo-EM Structure of a Nonenveloped Virus Reveals a Priming Mechanism for Cell Entry

被引:242
作者
Zhang, Xing [1 ]
Jin, Lei [1 ]
Fang, Qin [2 ]
Hui, Wong H. [3 ]
Zhou, Z. Hong [1 ,3 ]
机构
[1] Univ Calif Los Angeles, Dept Microbiol Mol Genet & Immunol, Los Angeles, CA 90095 USA
[2] Chinese Acad Sci, Wuhan Inst Virol, State Key Lab Virol, Wuhan 430071, Hubei, Peoples R China
[3] Univ Calif Los Angeles, Calif NanoSyst Inst, Los Angeles, CA 90095 USA
基金
美国国家卫生研究院;
关键词
GRASS CARP REOVIRUS; CAPSID PROTEIN MU-1; INFECTIOUS SUBVIRION PARTICLES; MEMBRANE-PENETRATION PROTEIN; ELECTRON CRYOMICROSCOPY; CRYOELECTRON MICROSCOPY; MAMMALIAN REOVIRUSES; PUTATIVE AUTOCLEAVAGE; IMAGE-RECONSTRUCTION; 3D RECONSTRUCTION;
D O I
10.1016/j.cell.2010.03.041
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
To achieve cell entry, many nonenveloped viruses must transform from a dormant to a primed state. In contrast to the membrane fusion mechanism of enveloped viruses (e.g., influenza virus), this membrane penetration mechanism is poorly understood. Here, using single-particle cryo-electron microscopy, we report a 3.3 angstrom structure of the primed, infectious subvirion particle of aquareovirus. The density map reveals side-chain densities of all types of amino acids (except glycine), enabling construction of a full-atom model of the viral particle. Our structure and biochemical results show that priming involves autocleavage of the membrane penetration protein and suggest that Lys84 and Glu76 may facilitate this autocleavage in a nucleophilic attack. We observe a myristoyl group, covalently linked to the N terminus of the penetration protein and embedded in a hydrophobic pocket. These results suggest a well-orchestrated process of nonenveloped virus entry involving autocleavage of the penetration protein prior to exposure of its membrane-insertion finger.
引用
收藏
页码:472 / 482
页数:11
相关论文
共 58 条
[31]   Structure of the reovirus membrane-penetration protein, μ1, in a complex with its protector protein, σ3 [J].
Liemann, S ;
Chandran, K ;
Baker, TS ;
Nibert, ML ;
Harrison, SC .
CELL, 2002, 108 (02) :283-295
[32]   The E-coli BtuCD structure:: A framework for ABC transporter architecture and mechanism [J].
Locher, KP ;
Lee, AT ;
Rees, DC .
SCIENCE, 2002, 296 (5570) :1091-1098
[33]   Thennostabilizing mutations in reovirus outer-capsid protein μ1 selected by heat inactivation of infectious subvirion particles [J].
Middleton, Jason K. ;
Agosto, Melina A. ;
Severson, Tonya F. ;
Yin, John ;
Nibert, Max L. .
VIROLOGY, 2007, 361 (02) :412-425
[34]   Accurate determination of local defocus and specimen tilt in electron microscopy [J].
Mindell, JA ;
Grigorieff, N .
JOURNAL OF STRUCTURAL BIOLOGY, 2003, 142 (03) :334-347
[35]   Trypsin-induced structural transformation in aquareovirus [J].
Nason, EL ;
Samal, SK ;
Prasad, BVV .
JOURNAL OF VIROLOGY, 2000, 74 (14) :6546-6555
[36]   Putative autocleavage of reovirus μ1 protein in concert with outer-capsid disassembly and activation for membrane permeabilization [J].
Nibert, ML ;
Odegard, AL ;
Agosto, MA ;
Chandran, K ;
Schiff, LA ;
Iff, S .
JOURNAL OF MOLECULAR BIOLOGY, 2005, 345 (03) :461-474
[37]   MAMMALIAN REOVIRUSES CONTAIN A MYRISTOYLATED STRUCTURAL PROTEIN [J].
NIBERT, ML ;
SCHIFF, LA ;
FIELDS, BN .
JOURNAL OF VIROLOGY, 1991, 65 (04) :1960-1967
[38]   A CARBOXY-TERMINAL FRAGMENT OF PROTEIN MU-1/MU-1C IS PRESENT IN INFECTIOUS SUBVIRION PARTICLES OF MAMMALIAN REOVIRUSES AND IS PROPOSED TO HAVE A ROLE IN PENETRATION [J].
NIBERT, ML ;
FIELDS, BN .
JOURNAL OF VIROLOGY, 1992, 66 (11) :6408-6418
[39]   Sequences of avian reovirus M1, M2 and M3 genes and predicted structure/function of the encoded μ proteins [J].
Noad, L ;
Shou, JY ;
Coombs, KM ;
Duncan, R .
VIRUS RESEARCH, 2006, 116 (1-2) :45-57
[40]   Putative autocleavage of outer capsid protein μ1, allowing release of myristoylated peptide μ1N during particle uncoating, is critical for cell entry by reovirus [J].
Odegard, AL ;
Chandran, K ;
Zhang, X ;
Parker, JSL ;
Baker, TS ;
Nibert, ML .
JOURNAL OF VIROLOGY, 2004, 78 (16) :8732-8745