The detailed mechanism of assembly of tobacco mosaic virus (TMV) and other viruses will be investigated by physical-chemical techniques. Both elementary step kinetics and equilibrium studies of TMV will continue in order to provide data sufficiently detailed to be interpreted in terms of the recently determined 2.9 Angstrom resolution structure of TMV. Through the use of various spectroscopic and hydrodynamic methods and optically detected stopped-flow and temperature-jump relaxation kinetics, as well as time-resolved low angle x-ray solution scattering, the mechanism of TMV assembly proposed previously by researchers at Cambridge, England and Strasbourg, France is being tested. Certain central aspects of the proposed mechanism appear to be inconsistent with experiment whereas some features are correct. Additional tests of this and an alternate mechanism will be performed. We seek to inquire into questions of the general kinetic principles governing virus assembly, the chemical and structural basis for coat protein recognition of RNA, the mechanism of viral disassembly and the coordinated regulation of virus synthesis and virus assembly. We are also interested in the dynamics of extended subunit systems and will continue to develop methods and kinetic analyses that may reveal general principles of their functionally important behavior.