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Prediction of HIV-1 Coreceptor Usage (Tropism) by Sequence Analysis using a Genotypic Approach
Published on: December 1, 2011
Caging the beast: TRIM5α binding to the HIV-1 core
1Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA. Felipe.Diaz-Griffero@einstein.yu.edu
Viruses
|October 14, 2011
Summary
The restriction factor TRIM5α forms a hexagonal array, or "cage," around the HIV-1 core, inhibiting infection. This discovery reveals how TRIM5α prevents viral replication by mimicking clathrin structures.
Area of Science:
- Virology
- Structural Biology
- Immunology
Background:
- The TRIM5α protein is a potent inhibitor of Human Immunodeficiency Virus type 1 (HIV-1) infection.
- TRIM5α functions by accelerating the uncoating of the HIV-1 capsid, a critical step in viral replication.
- TRIM5α's inhibitory activity relies on its ability to form higher-order self-association complexes, dependent on the B-box 2 domain, which enhance its avidity for the viral capsid.
Purpose of the Study:
- To investigate whether TRIM5α can assemble structures similar to clathrin cages around the HIV-1 core.
- To provide evidence for the structural basis of TRIM5α's antiviral mechanism.
Main Methods:
- Cryo-electron microscopy was used to visualize the interaction between TRIM5α and the HIV-1 capsid.
- Structural analysis focused on the self-assembly properties of TRIM5α and its arrangement on the viral core.
Main Results:
- TRIM5α was demonstrated to form a hexagonal array, effectively 'caging' the HIV-1 core.
- This hexagonal array structure is analogous to the protein cages formed by clathrin during endocytosis.
- The findings provide direct structural evidence for TRIM5α's mechanism of inhibiting HIV-1 infection.
Conclusions:
- TRIM5α actively cages the HIV-1 core through the formation of a hexagonal lattice.
- This structural mechanism is crucial for TRIM5α's ability to restrict HIV-1 replication.
- The discovery advances our understanding of TRIM5α as an antiviral restriction factor and its potential as a therapeutic target.
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