Micelle formation and crystallization as paradigms for virus assembly.

Self-assembly processes of crystallization, micelle formation and virus assembly, by their creation of geometric order from disordered components, represent first-order phase transitions that arise through the formation of partially ordered intermediates. The self-assembly of protein subunits into the geometric shells of polyhedral viruses may proceed through formation of reverse micelles, and be driven by condensation of encapsidated nucleic acid complexed with the amino terminal polypeptides of the coat proteins. Restructuring of subunits on the fluid, micellar surface, analogous to processes on the surfaces of growing crystals, then leads to symmetrical, icosahedral capsids. Such a pathway for viral assembly is attractive because it utilizes only physical properties inherent to the system, and it shares many characteristics that we know to be associated with those two other preeminent examples of self-assembly, micelles and crystals. Copyright 2005 Wiley periodicals, Inc.