Translational strategy of Solanum nodiflorum mottle virus RNA: synthesis of a coat protein precursor in vitro and in vivo.

Solanum nodiflorum mottle virus RNA (Mr = 1.5 X 10(6)) was translated in vitro in a wheat embryo extract. Four major products were synthesized: 2 related proteins of molecular weight 100K (P100) and 67K (P67), a protein of molecular weight 38K (P38), and a methionine-lacking protein of molecular weight 28K (P28). P38 was synthesized by a minor RNA component (Mr approximately 0.4 X 10(6)) and comigrated with the only viral product detected in SNMV-infected N. clevelandii protoplasts. Antiserum raised against purified SNMV virions precipitated both in vitro- and in vivo-synthesized P38, suggesting that it is either a precursor to or an intact form of SNMV coat protein whose apparent molecular weight in purified virus preparations is 30K.