The LC8-RavP ensemble Structure Evinces A Role for LC8 in Regulating Lyssavirus Polymerase Functionality

Area of Science:

• Virology and Molecular Biology
• Structural Biology

Background:

• Rabies and Ebola viruses utilize the conserved host protein LC8 for replication.
• The LC8 recognition motif in rabies virus phosphoprotein (RavP) is essential for viral lethality.

Purpose of the Study:

• To elucidate the molecular mechanism by which LC8 contributes to viral lethality.
• To investigate the structural and functional consequences of LC8 binding to RavP.

Main Methods:

• In vivo knockouts of the LC8 recognition motif in RavP.
• Cellular colocalization studies of RavP and LC8.
• Nuclear Magnetic Resonance (NMR), Small-Angle X-ray Scattering (SAXS), and molecular modeling.
• Analysis of viral polymerase functionality.

Main Results:

• RavP and LC8 colocalize in infected cells, and LC8 interaction is vital for viral polymerase function.
• LC8 binding to RavP restricts domain orientations, inducing a more active conformation.
• The LC8-bound RavP complex structure resembles that of a related, non-LC8-binding phosphoprotein.

Conclusions:

• LC8 acts as a molecular switch, inducing a functional conformation in RavP essential for viral replication.
• The conserved LC8 motif in Lyssavirus phosphoproteins and Ebola virus VP35 suggests a broader role for LC8 in regulating viral phosphoprotein functions.