title: Equilibrium self-assembly of small RNA viruses.
abstract: We propose a description for the quasiequilibrium self-assembly of small, single-stranded (ss) RNA viruses whose capsid proteins (CPs) have flexible, positively charged, disordered tails that associate with the negatively charged RNA genome molecules. We describe the assembly of such viruses as the interplay between two coupled phase-transition-like events: the formation of the protein shell (the capsid) by CPs and the condensation of a large ss viral RNA molecule. Electrostatic repulsion between the CPs competes with attractive hydrophobic interactions and attractive interaction between neutralized RNA segments mediated by the tail groups. An assembly diagram is derived in terms of the strength of attractive interactions between CPs and between CPs and the RNA molecules. It is compared with the results of recent studies of viral assembly. We demonstrate that the conventional theory of self-assembly, which does describe the assembly of empty capsids, is in general not applicable to the self-assembly of RNA-encapsidating virions.
authors.affiliation: Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.|Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Bruinsma
authors.affiliation: HIV Dynamics and Replication Program, National Cancer Institute, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702.
authors.forename: M
authors.initials: M
authors.lastname: Comas-Garcia
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Garmann
authors.affiliation: Department of Physics and Center for Soft Matter Research, New York University, 4 Washington Place, New York, New York 10003, USA.
authors.forename: A Y
authors.initials: AY
authors.lastname: Grosberg
mesh_terms: D001696:Biomechanical Phenomena; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism; D019277:Entropy; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation; D012328:RNA Viruses / Q000378:metabolism / Q000502:physiology*; D012367:RNA, Viral / Q000378:metabolism; D055672:Static Electricity; D013499:Surface Properties; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins; D012367:RNA, Viral