Replication of mycoplasmavirus MVL51 V. In vivo synthesis of virus-specific proteins

Abstract

MVL51 is a nonlytic bullet-shaped mycoplasmavirus containing circular single-stranded DNA of 2 × 10 6 daltons. In vivo synthesis of virus-specific proteins has been studied in Acholeplasma laidlawii wild-type and REP − cells. REP − cells propagate double-stranded DNA but not single-stranded DNA mycoplasma viruses. Cells were uv irradiated to suppress synthesis of cell proteins, infected, and incubated in medium containing radioisotopically labeled leucine. Proteins were extracted and analyzed by gel electrophoresis. Six virus-specific proteins have been identified, with molecular weights of 70,000, 50,000, 30,000, 19,000, 14,000, and 10,000. The four larger proteins correspond to the four viral structural proteins. The 14,000 dalton protein may have a role in the replication of double stranded DNA viral replicative intermediates. The amount of 10,000 dalton protein is maximal during progeny viral single-stranded DNA synthesis.