Structure of bile acid transporter NTCP crucial for hepatitis B virus entry

Continual an infection with hepatitis B virus (HBV), affecting greater than 290 million individuals worldwide, is a serious reason for cirrhosis and hepatocellular carcinoma and ends in an estimated 820,000 human deaths yearly1,2. Institution of HBV an infection requires a molecular interplay between the virus envelope glycoprotein L (LHBs) and the host entry receptor sodium-taurocholate co-transporting polypeptide (NTCP), a sodium-dependent bile acid transporter from blood to hepatocytes 3. Nevertheless, the molecular foundation for the virus-transporter interplay is poorly understood. Right here, we report the cryo-electron microscopy (cryo-EM) buildings of human, bovine, and rat NTCPs within the apo state, which reveals the presence of a tunnel throughout the membrane and a doable transport route for the substrate. Furthermore, the cryo-EM construction of human NTCP within the presence of myristoylated preS1 area of LHBs along with mutation and transport assays counsel a binding mode whereby preS1 and the substrate compete for the extracellular opening of the tunnel in NTCP. Importantly, the preS1 area interplay evaluation allows a mechanistic interpretation of naturally occurring HBV-insusceptible mutations in human NTCP. Taken collectively, our findings present structural framework for HBV recognition and for mechanistic understanding of sodium-dependent bile acid translocation by mammalian NTCPs.

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