Jae-Hyun Park, Masashi Iwamoto, Ji-Hye Yun, Tomomi Uchikubo-Kamo, Donghwan Son, Zeyu Jin, Hisashi Yoshida, Mio Ohki, Naito Ishimoto, Kenji Mizutani, Mizuki Oshima, Masamichi Muramatsu, Takaji Wakita, Mikako Shirouzu, Kehong Liu, Tomoko Uemura, Norimichi Nomura, So Iwata, Koichi Watashi, Jeremy R H Tame, Tomohiro Nishizawa, Weontae Lee, Sam-Yong Park
Nature 606(7916) 1027-1031 2022年5月17日 査読有り
Roughly 250 million people are infected with hepatitis B virus (HBV) worldwide1, and perhaps 15 million also carry the satellite virus HDV, which confers even greater risk of severe liver disease2. Almost ten years ago the HBV receptor was identified as NTCP (sodium taurocholate co-transporting polypeptide), which interacts directly with the first 48 amino acid residues of the N-myristoylated N-terminal preS1 domain of the viral large (L) protein3. Despite the pressing need for therapeutic agents to counter HBV, the structure of NTCP remains unsolved. This 349-residue protein is closely related to human apical sodium-dependent bile acid transporter (ASBT), another member of the solute carrier family SLC10. Crystal structures have been reported of similar bile acid transporters from bacteria4, 5, and these models with ten transmembrane helices are believed to resemble strongly both NTCP and ASBT. Using cryo-electron microscopy we have solved the structure of NTCP bound to an antibody, clearly showing the transporter has no equivalent to the first transmembrane helix of other SLC10 models, leaving the N-terminus exposed on the extracellular face. Comparison of the different structures indicates a common mechanism of bile acid transport, but the NTCP structure also displays a pocket formed by residues known to interact with preS1, presenting new and enticing opportunities for structure-based drug design.