The p66 immature precursor of HIV-1 reverse transcriptase

Area of Science:

• Structural biology
• Virology
• Biochemistry

Background:

• The mature human immunodeficiency virus type 1 reverse transcriptase (RT) has extensive structural data.
• The structure of the p66 precursor homodimer remains elusive.
• The maturation process of HIV-1 RT is not fully understood due to inaccessible processing sites in mature structures.

Purpose of the Study:

• To investigate the conformation of the human immunodeficiency virus type 1 reverse transcriptase (RT) p66 homodimer.
• To provide insights into the maturation mechanism of HIV-1 RT.

Main Methods:

• Solution Nuclear Magnetic Resonance (NMR) spectroscopy was employed.
• The conformation of the RT p66 homodimer was analyzed.

Main Results:

• The Ribonuclease H (RNH) and Thumb domains of the p66 homodimer are folded.
• The conformations of these domains are highly similar to those found in the mature RT.
• This structural similarity suggests a more ordered precursor state than previously hypothesized.

Conclusions:

• The folded nature of the p66 homodimer's RNH and Thumb domains challenges maturation models that propose a largely unfolded precursor.
• The study provides a structural basis for future mechanistic investigations into HIV-1 RT maturation at the atomic level.