Plate Tectonics of Virus Shell Assembly and Reorganization in Phage Φ8, a Distant Relative of Mammalian Reoviruses

DOI: 10.1016/j.str.2013.06.017
PMID: 23891291

Authors: Kamel El Omari (The Wellcome Trust Centre for Human Genetics, University of Oxford) , Geoff Sutton (The Wellcome Trust Centre for Human Genetics, University of Oxford) , Janne j. Ravantti (Institute of Biotechnology and Department of Biosciences, University of Helsinki) , Hanwen Zhang (The Wellcome Trust Centre for Human Genetics, University of Oxford) , Thomas S. Walter (The Wellcome Trust Centre for Human Genetics, University of Oxford) , Jonathan M. Grimes (The Wellcome Trust Centre for Human Genetics, University of Oxford; Diamond Light Source) , Dennis h. Bamford (Institute of Biotechnology and Department of Biosciences, University of Helsinki) , David I. Stuart (Diamond Light Source) , Erika J. Mancini (The Wellcome Trust Centre for Human Genetics, University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Structure

State: Published (Approved)
Published: July 2013

Abstract: The hallmark of a virus is its capsid, which harbors the viral genome and is formed from protein subunits, which assemble following precise geometric rules. dsRNA viruses use an unusual protein multiplicity (120 copies) to form their closed capsids. We have determined the atomic structure of the capsid protein (P1) from the dsRNA cystovirus Φ8. In the crystal P1 forms pentamers, very similar in shape to facets of empty procapsids, suggesting an unexpected assembly pathway that proceeds via a pentameric intermediate. Unlike the elongated proteins used by dsRNA mammalian reoviruses, P1 has a compact trapezoid-like shape and a distinct arrangement in the shell, with two near-identical conformers in nonequivalent structural environments. Nevertheless, structural similarity with the analogous protein from the mammalian viruses suggests a common ancestor. The unusual shape of the molecule may facilitate dramatic capsid expansion during phage maturation, allowing P1 to switch interaction interfaces to provide capsid plasticity.

Subject Areas: Biology and Bio-materials

Facility: ESRF, SLS

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