The structure of the Lujo virus spike complex

Area of Science:

• Virology
• Structural Biology
• Molecular Interactions

Background:

• Lujo virus (LUJV) is a highly pathogenic arenavirus responsible for severe hemorrhagic fever outbreaks.
• LUJV utilizes neuropilin-2 (NRP2) as its cell-entry receptor, distinct from other Old World and New World arenaviruses.
• The structural organization of the LUJV spike complex and its interaction with NRP2 remained uncharacterized.

Purpose of the Study:

• To determine the structure of the membrane-embedded Lujo virus spike complex.
• To elucidate the mechanism by which LUJV engages with its distinct cell-entry receptor, NRP2.
• To provide insights into arenavirus evolution and inform strategies for combating future outbreaks.

Main Methods:

• Cryo-electron microscopy (cryo-EM) was employed to determine the structure of the LUJV spike complex.
• Structural analysis identified the binding site and stoichiometry of NRP2 interaction.
• Quantum mechanical modeling was used to analyze the specific arginine-methionine interaction involved in receptor binding.

Main Results:

• The cryo-EM structure revealed the overall organization of the trimeric LUJV spike complex.
• A single NRP2 molecule was observed bound at the apex of the trimeric spike, with multiple subunits engaging the receptor.
• An arginine-methionine interaction was identified as crucial for NRP2 binding, further analyzed by quantum mechanical methods.

Conclusions:

• The determined structure provides the first detailed view of the LUJV spike complex bound to its receptor.
• Comparison with the Lassa virus spike structure offers insights into arenavirus evolution.
• Understanding the LUJV-NRP2 interaction mechanism is critical for developing effective vaccines and antiviral strategies against arenavirus infections.