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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
Ribonuclease H: properties, substrate specificity and roles in retroviral reverse transcription
James J Champoux1, Sharon J Schultz
1Department of Microbiology, University of Washington, Seattle, WA 98195, USA. champoux@u.washington.edu
The FEBS Journal
|February 21, 2009
Summary
Retroviral reverse transcriptases have unique RNase H activities essential for viral RNA degradation and DNA synthesis. These enzymes precisely cleave RNA/DNA hybrids, facilitating crucial steps in the retroviral life cycle.
Area of Science:
- Molecular Biology
- Virology
- Enzymology
Background:
- Retroviral reverse transcriptases contain DNA polymerase and RNase H activities.
- Retroviral RNase H exhibits unique properties distinct from cellular RNases H.
Purpose of the Study:
- To elucidate the specific cleavage mechanisms and properties of retroviral RNase H.
- To understand the role of retroviral RNase H in reverse transcription.
Main Methods:
- Analysis of retroviral RNase H enzymatic activities.
- Characterization of substrate specificities and cleavage patterns.
Main Results:
- Retroviral RNase H displays endonuclease activity on DNA/RNA hybrids.
- Cleavage is directed by DNA 3' recessed and RNA 5' recessed ends.
- Sequence preferences near cleavage sites influence enzyme activity.
Conclusions:
- Retroviral RNase H plays a critical role in degrading the viral RNA genome post-minus-strand synthesis.
- These enzymes precisely generate primers for plus-strand DNA synthesis.
- Retroviral RNase H facilitates plus-strand initiation and primer removal during reverse transcription.
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