Data from: Phospholipid-driven conformational switching of HCV NS5A links protein folding to replication membrane remodeling

Phospholipids are essential for RNA virus replication, yet their role in
modulating conformational dynamics of membrane-associated viral proteins
remains poorly understood. For NS5A, a key replication factor of hepatitis
C virus, previous crystallographic models fail to capture the lipid-driven
conformational mechanics we uncover here. Using structural informatics and
biochemical probing of pharmacophore-guided mutants in defined lipid
environments, we evaluated competing NS5A domain 1 dimerization models.
Our data reveal an alternative membrane-specific fold stabilized by
polyproline hinges and phospholipids (PIPs) such as
phosphatidylinositol-4-phosphate, a host lipid enriched at replication
membranes. PIP binding promotes a conformational switch that drives
dimerization, linking lipid sensing to membrane remodeling and host factor
recruitment. This reciprocal mechanism—where a lipid allosterically
modulates a viral protein that reshapes membranes—is blocked by the
antiviral Pibrentasvir. These findings define a lipid-driven structural
switch that governs NS5A pleiotropy and highlight dynamic lipid–protein
interfaces as targets for antiviral intervention.