Figure 7.  A close look at the structure of Tobacco mosaic virus (TMV). TMV is made up of a spiral or helix of 2,130 coat protein (CP) subunits and a single-stranded positive sense RNA of approximately 6400 nucleotides. Two views of TMV particles show the relationships between the CP subunits and the single-stranded TMV RNA. [Note: 10 Å = 1 nm] (Courtesy APS) BACK