Reverse transcription of a naturally occurring nonretroviral RNA produces a precise deletion in the majority of its cDNA products.
A precise, reproducible deletion made during in vitro reverse transcription of RNA2 from the icosahedral positive-stranded Helicoverpa armigera stunt virus (Tetraviridae) is described. The deletion, located between two hexamer repeats, is a 50-base sequence that includes one copy of the hexamer repeat. Only the Moloney murine leukemia virus reverse transcriptase and its derivative Superscript I, carrying a deletion of the carboxy-terminal RNase H region, showed this response, indicating a template-switching mechanism different from one proposed that involves a RNase H-dependent strand transfer. Superscript II, however, which carries point mutations to reduce RNase H activity, does not cause a deletion. A possible mechanism involves the enzyme pausing at the 3' side of a stem-loop structure and the 3' end of the nascent DNA strand separating from the template and reannealing to the upstream hexamer repeat.
Johnson
K N
KN
CSIRO Entomology, Canberra, Australia.
Gordon
K H
KH
Hanzlik
T N
TN
D001483:Base Sequence; D004261:DNA Replication; D018076:DNA, Complementary / Q000378:metabolism*; D004279:DNA, Viral; D017353:Gene Deletion; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000201:enzymology / Q000235:genetics; D009690:Nucleic Acid Conformation; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016914:Ribonuclease H / Q000235:genetics; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014780:Viruses / Q000201:enzymology / Q000235:genetics
D018076:DNA, Complementary; D004279:DNA, Viral; D012313:RNA; D016914:Ribonuclease H