The three-dimensional structure of genomic RNA in bacteriophage MS2: implications for assembly.
Using cryo-electron microscopy, single particle image processing and three-dimensional reconstruction with icosahedral averaging, we have determined the three-dimensional solution structure of bacteriophage MS2 capsids reassembled from recombinant protein in the presence of short oligonucleotides. We have also significantly extended the resolution of the previously reported structure of the wild-type MS2 virion. The structures of recombinant MS2 capsids reveal clear density for bound RNA beneath the coat protein binding sites on the inner surface of the T=3 MS2 capsid, and show that a short extension of the minimal assembly initiation sequence that promotes an increase in the efficiency of assembly, interacts with the protein capsid forming a network of bound RNA. The structure of the wild-type MS2 virion at approximately 9 A resolution reveals icosahedrally ordered density encompassing approximately 90% of the single-stranded RNA genome. The genome in the wild-type virion is arranged as two concentric shells of density, connected along the 5-fold symmetry axes of the particle. This novel RNA fold provides new constraints for models of viral assembly.
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
Katerina
K
Toropova
Gabriella
G
Basnak
Reidun
R
Twarock
Peter G
PG
Stockley
Neil A
NA
Ranson
D001665:Binding Sites; D002213:Capsid / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D019281:Dimerization; D007700:Kinetics; D017909:Levivirus / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012317:RNA Phages / Q000737:chemistry* / Q000648:ultrastructure; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000378:metabolism / Q000648:ultrastructure; D014771:Virion / Q000737:chemistry / Q000648:ultrastructure
D036022:Capsid Proteins; D012367:RNA, Viral; D011994:Recombinant Proteins