In reticulocyte lysates a predominant protein of apparent molecular weight 116,000 (116K) was synthesized from tobacco ringspot virus RNA-2 and proteins of 225K and 205K were synthesized from RNA-1. In time-course experiments using unfractionated RNA the levels of nine additional proteins of 195K, 135K, 92K, 77K, 65K, 53K, 40K, 30K, and 23K increased with time. The levels of these nine proteins relative to the 225K, 205K, and 116K proteins decreased when unfractionated RNA was translated in reticulocyte lysates in the presence of the amino acid analogs canavanine, S-aminoethylcysteine, and p-fluorophenylalanine. A protease induced in the reticulocyte lysates by RNA-1 catalyzed cleavage of the 116K protein into proteins of 53K, 40K, and 23K. Proteins of 116K, 77K, and 53K were immunoprecipitated with antiserum to tobacco ringspot virus particles.