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Updated: Jun 6, 2026
08:21
Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle (GUV) Membranes
Published on: July 28, 2016
HIV-1 Gag extension: conformational changes require simultaneous interaction with membrane and nucleic acid.
Siddhartha A K Datta1, Frank Heinrich, Sindhu Raghunandan
1HIV Drug Resistance Program, National Cancer Institute, PO Box B, Building 535, Fredrick, MD 21702-1201, USA.
Journal of Molecular Biology
|December 8, 2010
Summary
Human immunodeficiency virus type 1 (HIV-1) Gag protein undergoes significant conformational changes during viral assembly. Key interactions with protein, RNA, and membranes drive Gag extension, crucial for virus formation.
Area of Science:
- Structural biology
- Virology
- Biophysics
Background:
- The retroviral Gag polyprotein is essential for viral assembly, interacting with viral RNA, other Gag proteins, and the cell membrane.
- Intrinsically disordered regions in Gag complicate structural characterization, with previous studies showing compact conformations in solution but rod-shaped structures in immature virions.
Purpose of the Study:
- To investigate the conformational flexibility of HIV-1 Gag protein.
- To identify molecular interactions that mediate Gag extension during viral assembly.
- To characterize Gag conformations at a membrane interface.
Main Methods:
- Neutron scattering and neutron reflectivity.
- Molecular modeling.
- Recapitulation of key assembly interactions.
Main Results:
- Identified interactions that reversibly extend the Gag protein.
- Demonstrated advanced neutron reflectivity techniques to resolve Gag conformations on membranes.
- Provided evidence that basic residues on N- and C-terminal domains facilitate binding to membranes and nucleic acids.
Conclusions:
- HIV-1 Gag protein undergoes substantial conformational changes, transitioning from compact states to extended forms.
- Simultaneous interactions of Gag with protein, nucleic acid, and membrane components are necessary for full protein extension and viral assembly.
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