The polarity of assembly of papaya mosaic virus and tobacco mosaic virus RNAs with PMV-protein under conditions of nonspecificity.

The problem of the rapid multiinitiation of papaya mosaic virus or tobacco mosaic virus RNA by PMV-protein near pH 7.0 at low ionic strength has been overcome. If NaCl is added to 0.1 M, both RNAs are first encapsidated at their respective 5' ends. This shows that the initial site of helix formation depends on the protein rather than the RNA.