The 80K polypeptide associated with the replication complexes of cauliflower mosaic virus is recognized by antibodies to gene V translation product

The enzyme responsible for cauliflower mosaic virus (CaMV) DNA replication has been studied by isolating virus replication complexes and assaying the associated polymerase activity using activated calf thymus DNA or poly(rCm)'oligo(dG)lz_t8 as template-primer. The activity of the enzyme was specifically inhibited by immune serum raised against a synthetic peptide corresponding to a portion of the viral gene V protein. This result provides further ev idenw that this protein is the reverse transcriptase involved in CaMV replication. A model for cauliflower mosaic virus (CaMV) replication has been proposed (Guilley et al., 1983; Hull & Covey, 1983; Pfeiffer & Hohn, 1983) which involves reverse transcription ofa viral transcript. In this model, a major CaMV DNA transcript, 35S RNA, is transcribed in the first step of the replication process into cDNA starting from a tRNA primer binding site. Indeed, Volovitch et al. (1984) have demonstrated the presence in infected plants of a reverse transcriptase activity not detected inhealthy plants. Toh et al. (1983) and Volovitch et al. (1984) have shown that the open reading frame (ORF) V polypeptide shares significant homology with reverse transcriptase from hepatitis B virus and avian retrovirus. From the CaMV nucleotid