Abstract: | The 3' terminus of the strand (minus strand) complementary to poliovirion RNA (plus strand) has been examined to see whether this sequence extends to the 5'-nucleotide terminus of the plus strand, or whether minus-strand synthesis terminates prematurely, perhaps due to the presence of a nonreplicated nucleotide primer for initiation of plus-strand synthesis. The 3' terminus was labeled with 32P using 5'-32P]pCp and RNA ligase, and complete RNase digests were performed with RNases A, T1, and U2. 32P-oligonucleotides were analyzed for size by polyacrylamide-urea gel electrophoresis. The major oligonucleotide products formed were consistent with the minus strand containing 3' ends complementary and flush with the 5' end of the plus strand. However, a variable proportion of the isolated minus strands from different preparations were heterogeneous in length and appeared to differ from each other by the presence of one, two, or three 3'-terminal A residues. |