Viral reverse transcriptases

Area of Science:

• Molecular Biology
• Virology
• Enzymology

Background:

• Reverse transcriptases (RTs) are essential enzymes for the replication of viruses in the Retroviridae, Metaviridae, Pseudoviridae, Hepadnaviridae, and Caulimoviridae families.
• RTs possess DNA polymerase and ribonuclease H activities, critical for converting RNA into DNA and integrating it into host genomes.
• These enzymes are known for high error rates and low processivity, contributing to viral mutation and recombination.

Purpose of the Study:

• To review current knowledge on reverse transcription mechanisms in five major virus families.
• To summarize available biochemical and structural data on reverse transcriptases.
• To discuss the potential for inhibiting RT enzymatic activities for therapeutic purposes.

Main Methods:

• Literature review of scientific publications on reverse transcriptases and reverse transcription.
• Analysis of structural and biochemical data from studies on various RT enzymes.
• Synthesis of information regarding the enzymatic activities, biosynthesis, and inhibition of RTs.

Main Results:

• RTs exhibit diverse quaternary structures (monomers, homodimers, heterodimers) and play distinct roles in viral replication cycles.
• Inhibition of HIV-1 RT polymerase activity is central to current antiretroviral therapy, highlighting the therapeutic potential of targeting RTs.
• Limited structural and biochemical data exist for Hepadnaviridae and Caulimoviridae RTs, though cross-inhibition with HIV-1 RT drugs is observed.

Conclusions:

• Reverse transcription is a vital process for multiple virus families, with RTs being key targets for antiviral drug development.
• Further structural and biochemical characterization of RTs, especially from Hepadnaviridae and Caulimoviridae, is needed.
• Developing novel inhibitors, including ribonuclease H inhibitors, is crucial for combating viral infections like HIV.