Immune-evading HIV Protein Complex Structure is Determined by Researchers

The HIV-1 infection can kill cellular defenses with its viral infectivity factor (Vif). OIST specialists Prof. Matthias Wolf and Dr. Takahide Kouno along with a global group of associates have now resolved the atomic structure of the APOBEC3G-Vif complex using cryo-electron microscopy.

“APOBEC3G (A3G) is a key component of the human innate immune system to defend against invading viruses, getting a ride inside budding virions like in a Trojan horse so that it can modify and disable viral DNA after reverse transcription in infected cells,” explains Prof. Wolf, the senior author of the study and who leads the OIST Molecular Cryo-Electron Microscopy Unit.

“But HIV-1 has evolved a counteraction mechanism in the form of its Vif protein, which inhibits this process by binding to and degrading A3G, leading to successful amplification of infectious viral particles.”

A novel part of their review is the principal show that this complex formation is intervened by unambiguous RNA sequences, despite the fact that single-stranded DNA is the substrate of degradation by A3G. Their protein build was optimized for higher solvency and could repeat the degradation pathway by A3G ubiquitination (a process that includes the transfer of ubiquitin polyubiqitination to a target protein and is significant in numerous physiological functions) in vitro.

The work recognized explicit associations between protein and the RNA ligand, which might be designated with drugs for future antiviral treatments against HIV/AIDS that inhibit the A3G-Vif interaction.