PROTEIN-RNA INTERACTIONS IN TOBACCO MOSAIC VIRUS

Tobacco mosaic virus (TMV) is a rod-shaped virus, 3,000 A long and 180 A in diameter. It has helical symmetry, with 49 coat protein subunits in three turns. A single strand of RNA follows the basic helix at 40 A radius, with three nucleotides bound to each protein subunit. See Caspar (1963) for a review of early work