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Updated: Jul 11, 2026

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
13:07

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

Published on: January 30, 2019

Onconase action on tRNA(Lys3), the primer for HIV-1 reverse transcription

Avvaru N Suhasini1, Ravi Sirdeshmukh

  • 1Center for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.

Biochemical and Biophysical Research Communications
|September 25, 2007
PubMed

Insights

Onconase, an antitumor enzyme, inhibits HIV-1 replication by targeting cellular transfer RNA (tRNA). It cleaves tRNA primarily in the variable loop, suggesting structural factors influence its action.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Virology

Background:

  • Onconase is a cytotoxic ribonuclease with antitumor properties.
  • It inhibits viral replication in HIV-1-infected cells.
  • Cellular transfer RNA (tRNA) is a potential target for Onconase.

Purpose of the Study:

  • To investigate Onconase's cleavage specificity on tRNA(Lys3), a primer for HIV-1 reverse transcription.
  • To determine if Onconase targets specific sequences or structural features in tRNA(Lys3).

Main Methods:

  • In vitro transcription of tRNA(Lys3).
  • Analysis of Onconase cleavage sites on tRNA(Lys3) using mutated sequences.
  • Comparison of cleavage patterns with previously identified Onconase targets.

Main Results:

  • Onconase predominantly cleaved tRNA(Lys3) at GG residues within a GGG triplet in the variable loop.
  • Cleavage occurred despite the absence of the previously identified UGG sequence context.
  • Mutations at the cleavage site did not alter Onconase's activity.

Conclusions:

  • Onconase exhibits cleavage specificity in tRNA(Lys3) primarily within the variable loop.
  • Sequence context (UGG) is not the sole determinant; structural elements likely contribute to Onconase's selective tRNA cleavage.
  • These findings advance understanding of Onconase's mechanism of action against HIV-1 replication.

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