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Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
Published on: March 22, 2016
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A supramolecular assembly mediates lentiviral DNA integration
Allison Ballandras-Colas1, Daniel P Maskell1, Erik Serrao2,3
1Chromatin Structure and Mobile DNA, The Francis Crick Institute, London, NW1 1AT, UK.
Science (New York, N.Y.)
|January 7, 2017
Summary
Researchers visualized the maedi-visna lentivirus intasome using cryo-electron microscopy. This structure reveals how retroviral integrase (IN) forms complexes for DNA insertion, aiding HIV-1 IN inhibitor design.
Area of Science:
- Structural Biology
- Virology
- Molecular Biology
Background:
- Retroviral integrase (IN) is essential for viral DNA integration into host chromatin.
- The intasome is the functional nucleoprotein complex where IN catalyzes viral DNA insertion.
- Understanding intasome structure is key to inhibiting retroviral replication.
Purpose of the Study:
- To visualize the functional maedi-visna lentivirus intasome structure at high resolution.
- To elucidate the architecture of the IN complex and its catalytic mechanism.
- To provide insights for the development of novel antiviral therapies.
Main Methods:
- Cryo-electron microscopy (cryo-EM) was employed to determine the intasome structure.
- High-resolution imaging (4.9 angstroms) allowed detailed visualization of the complex.
- Structural analysis focused on the homo-hexadecameric assembly of IN.
Main Results:
- The maedi-visna lentivirus intasome exhibits a tetramer-of-tetramers architecture, a homo-hexadecamer of IN.
- Eight distinct IN protomer types were identified, supporting two catalytically active subunits.
- A conserved intasomal core is formed by two IN tetramers, with C-terminal domains completing the synaptic interface.
Conclusions:
- The study explains how HIV-1 IN forms functional intasomes through higher-order multimerization.
- These findings reconcile previous biochemical and structural data on HIV-1 IN.
- The lentiviral intasome structure provides a platform for designing targeted HIV-1 IN inhibitors.
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