Uncovering The Self-Assembly Mechanism Of Hepatitis B Virus At The Single-Molecule Level

The concerted self-assembly of biomacromolecules into ordered supramolecular structures is essential for many biological processes. For instance, a variety of viruses rely on a self-assembly strategy to form their protective protein shell, the capsid, during the initial stages of the viral life cycle. Although capsid formation is a crucial step to ensure infectivity and viral propagation, this process still remains poorly understood. The work presented here focuses on unravelling the molecular mechanisms underlying the assembly of Hepatitis B virus (HBV) capsid protein around nucleic acids. Specifically, we have combined single-molecule techniques such as optical tweezers, fluorescence microscopy, and high-speed atomic force microscopy to follow HBV self-assembly in real time with single-molecule resolution. Our results demonstrate that the HBV capsid protein exhibits DNA folding capabilities and that capsid assembly occurs through the active packaging of nucleic acid. Furthermore, the assembly footprint of the HBV capsid protein is disclosed and structural data of early assembly intermediates is provided, finally elucidating the crucial first steps in the assembly pathway of HBV.