The HIV intasome is a large nucleoprotein assembly that mediates the integration of a DNA copy of the viral genome into host chromatin. Intasomes are targeted by the latest generation of antiretroviral drugs, integrase strand-transfer inhibitors (INSTIs). Challenges associated with lentiviral intasome biochemistry have hindered high-resolution structural studies of how INSTIs bind to their native drug target. Here, we present high-resolution cryo-electron microscopy structures of HIV intasomes bound to the latest generation of INSTIs. These structures highlight how small changes in the integrase active site can have notable implications for drug binding and design and provide mechanistic insights into why a leading INSTI retains efficacy against a broad spectrum of drug-resistant variants. The data have implications for expanding effective treatments available for HIV-infected individuals.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7357238 | PMC |
http://dx.doi.org/10.1126/science.aay8015 | DOI Listing |
Viruses
July 2024
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Retroviral integration is mediated by intasome nucleoprotein complexes wherein a pair of viral DNA ends are bridged together by a multimer of integrase (IN). Atomic-resolution structures of HIV-1 intasomes provide detailed insights into the mechanism of integration and inhibition by clinical IN inhibitors. However, previously described HIV-1 intasomes are highly heterogeneous and have the tendency to form stacks, which is a limiting factor in determining high-resolution cryo-EM maps.
View Article and Find Full Text PDFJ Biol Chem
June 2024
Department of Integrated Structural Biology, Chromatin Stability and DNA Mobility, IGBMC, U-596 INSERM, UMR-7104 CNRS, University of Strasbourg, Illkirch Cedex, France; GDR CNRS 2194 "DYNAVIR" (Viral DNA Integration and Chromatin Dynamics Network), France. Electronic address:
The pre-integration steps of the HIV-1 viral cycle are some of the most valuable targets of recent therapeutic innovations. HIV-1 integrase (IN) displays multiple functions, thanks to its considerable conformational flexibility. Recently, such flexible proteins have been characterized by their ability to form biomolecular condensates as a result of Liquid-Liquid-Phase-Separation (LLPS), allowing them to evolve in a restricted microenvironment within cells called membrane-less organelles (MLO).
View Article and Find Full Text PDFJ Mol Biol
May 2024
Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
Retroviral DNA integration is mediated by nucleoprotein complexes (intasomes) in which a pair of viral DNA ends are bridged by a multimer of integrase (IN). Most of the high-resolution structures of HIV-1 intasomes are based on an HIV-1 IN with an Sso7d protein domain fused to the N-terminus. Sso7d-IN aggregates much less than wild-type IN and has been critical for structural studies of HIV-1 intasomes.
View Article and Find Full Text PDFbioRxiv
January 2024
The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
Integrase (IN) performs dual essential roles during HIV-1 replication. During ingress, IN functions within an oligomeric "intasome" assembly to catalyze viral DNA integration into host chromatin. During late stages of infection, tetrameric IN binds viral RNA and orchestrates the condensation of ribonucleoprotein complexes into the capsid core.
View Article and Find Full Text PDFViruses
January 2024
Department of Chemistry and Physical Sciences, Pace University, New York, NY 10038, USA.
The first- and second-generation clinically used HIV-1 integrase (IN) strand transfer inhibitors (INSTIs) are key components of antiretroviral therapy (ART), which work by blocking the integration step in the HIV-1 replication cycle that is catalyzed by a nucleoprotein assembly called an intasome. However, resistance to even the latest clinically used INSTIs is beginning to emerge. Developmental third-generation INSTIs, based on naphthyridine scaffolds, are promising candidates to combat drug-resistant viral variants.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!