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-Structure paper
Title | Slowly folding surface extension in the prototypic avian hepatitis B virus capsid governs stability. |
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Journal, issue, pages | Elife, Vol. 9, Year 2020 |
Publish date | Aug 14, 2020 |
Authors | Cihan Makbul / Michael Nassal / Bettina Böttcher / |
PubMed Abstract | Hepatitis B virus (HBV) is an important but difficult to study human pathogen. Most basics of the hepadnaviral life-cycle were unraveled using duck HBV (DHBV) as a model although DHBV has a capsid ...Hepatitis B virus (HBV) is an important but difficult to study human pathogen. Most basics of the hepadnaviral life-cycle were unraveled using duck HBV (DHBV) as a model although DHBV has a capsid protein (CP) comprising ~260 rather than ~180 amino acids. Here we present high-resolution structures of several DHBV capsid-like particles (CLPs) determined by electron cryo-microscopy. As for HBV, DHBV CLPs consist of a dimeric α-helical frame-work with protruding spikes at the dimer interface. A fundamental new feature is a ~ 45 amino acid proline-rich extension in each monomer replacing the tip of the spikes in HBV CP. In vitro, folding of the extension takes months, implying a catalyzed process in vivo. DHBc variants lacking a folding-proficient extension produced regular CLPs in bacteria but failed to form stable nucleocapsids in hepatoma cells. We propose that the extension domain acts as a conformational switch with differential response options during viral infection. |
External links | Elife / PubMed:32795390 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.0 - 6.2 Å |
Structure data | EMDB-10800, PDB-6ygh: EMDB-10801: EMDB-10802: EMDB-10803, PDB-6ygi: |
Source |
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Keywords | VIRUS LIKE PARTICLE / duck hepatitis B core protein / extension domain / spike / slowly folding |