Oligomeric HIV-1 integrase structures reveal functional plasticity for intasome assembly and RNA binding

Area of Science:

• Structural Biology
• Virology
• Molecular Biology

Background:

• HIV-1 integrase (IN) is crucial for viral replication, performing distinct roles in DNA integration and viral RNA binding.
• The molecular architectures of IN assemblies mediating these functions are not fully understood.
• The IN tetramer is a key target for developing allosteric inhibitors.

Purpose of the Study:

• To determine the cryo-EM structures of HIV-1 IN tetramers and intasome hexadecamers.
• To elucidate the molecular mechanisms underlying IN's dual functions and oligomeric plasticity.
• To provide structural insights for the development of novel antiviral therapies.

Main Methods:

• Cryo-electron microscopy (cryo-EM) to resolve high-resolution structures.
• Biochemical assays to investigate IN assembly and function.
• Structural analysis of wildtype HIV-1 IN tetramers and intasome hexadecamers.

Main Results:

• Determined cryo-EM structures of HIV-1 IN tetramers and intasome hexadecamers.
• Revealed significant plasticity in IN structures, enabling distinct oligomeric assembly.
• Identified a conserved interface linking IN functions to tetramerization.

Conclusions:

• HIV-1 IN plasticity allows assembly into functionally distinct oligomeric forms.
• IN's dual roles are associated with tetramerization, providing a basis for its functions.
• Structural data offers blueprints for designing improved allosteric IN inhibitors.