Characterization of the cDNA synthesized by avian retrovirus reverse transcriptase using 35 S avian myeloblastosis virus RNA and an exogenous bovine primer tRNA.

Bovine tRNA(Trp) can be partially hybridized to the avian myeloblastosis virus (AMV) 35 S RNA at 37 degrees C, in the presence of AMV RNA-dependent DNA polymerase (reverse transcriptase). This template-primer complex is active in the synthesis of viral cDNA. The size of the cDNA products synthesized in the in vitro reconstituted AMV system was determined by urea-polyacrylamide gel electrophoresis using a tRNA labelled at the 3'-end by yeast tRNA nucleotidyl transferase. The synthesized cDNA has a size of about 100 nucleotides and was shown by Southern blotting to be complementary to a specific sequence of the 5'-end of the retroviral genome. These results indicate that reverse transcriptase is able to anneal the exogenous primer tRNA at the 'primer-binding site' near the 5'-end of the long terminal repeat (LTR) of AMV RNA.