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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

Biophysical and enzymatic properties of the simian and prototype foamy virus reverse transcriptases

Maximilian J Hartl1, Florian Mayr, Axel Rethwilm

  • 1Universität Bayreuth, Lehrstuhl für Struktur und Chemie der Biopolymere & Research, Center for Biomacromolecules, 95440 Bayreuth, Germany.

Retrovirology
|February 2, 2010
PubMed
Abstract

Insights

Foamy virus protease-reverse transcriptase (PR-RT) enzymes from SFVmac and PFV are monomeric proteins with similar biochemical properties. These findings clarify enzyme function and may explain differences in viral behavior in host cells.

Area of Science:

  • Virology
  • Enzymology
  • Molecular Biology

Background:

  • Foamy viruses synthesize Pol protein independently, unlike orthoretroviruses which produce a Gag-Pol precursor.
  • The mature foamy virus enzyme is a protease-reverse transcriptase (PR-RT), with the protease domain at the N-terminus.
  • Despite high homology, SFVmac and PFV PR-RTs exhibit distinct properties, including differential sensitivity to azidothymidine (AZT).

Purpose of the Study:

  • To directly compare the monomer/dimer status and enzymatic behavior of wild-type SFVmac and PFV PR-RT enzymes.
  • To elucidate the functional differences between these two closely related foamy virus enzymes.

Main Methods:

  • Purification of wild-type SFVmac and PFV PR-RT enzymes.
  • Determination of kinetic parameters for both enzymes.
  • Assessment of the monomer/dimer status of PFV PR-RT.

Main Results:

  • Both SFVmac and PFV PR-RT enzymes were purified and characterized.
  • Kinetic parameters for both enzymes were determined.
  • PFV PR-RT was confirmed to be a monomeric protein, similar to SFVmac PR-RT.

Conclusions:

  • SFV and PFV PR-RTs are monomeric proteins with comparable biochemical and biophysical properties.
  • These properties align with Murine Leukemia Virus (MLV) RT but differ from Human Immunodeficiency Virus type 1 (HIV-1) RT.
  • Observed differences may relate to the distinct cellular environments (dividing vs. non-dividing cells) encountered by these viruses.

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