Structural characterization of HIV-1 matrix mutants implicated in envelope incorporation

Area of Science:

• Virology
• Structural Biology
• Biochemistry

Background:

• HIV-1 assembly requires Gag polyproteins at the plasma membrane.
• The matrix (MA) domain of Gag mediates Gag assembly and envelope (Env) incorporation.
• Mutations in the MA trimer interface affect Env incorporation and HIV-1 infectivity.

Purpose of the Study:

• To investigate the structural and trimerization properties of HIV-1 MA mutant proteins.
• To understand the role of MA trimerization in Env incorporation.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy
• X-ray crystallography
• Analytical ultracentrifugation

Main Results:

• Mutations did not significantly alter MA overall structure or folding.
• Minor structural perturbations were observed at the MA trimer interface.
• Mutations had minimal impact on the MA monomer-trimer equilibrium.
• A novel intermolecular interaction involving Arg-63 was identified in the MA Q63R mutant structure.

Conclusions:

• MA trimerization mutations have subtle effects on MA structure and stability.
• The findings provide structural insights into MA-Env interactions and HIV-1 assembly.
• This research advances understanding of the interplay between MA trimerization and Env incorporation.