HBV RNA pre-genome encodes specific motifs that mediate interactions with the viral core protein that promote nucleocapsid assembly

TY - JOUR

T1 - HBV RNA pre-genome encodes specific motifs that mediate interactions with the viral core protein that promote nucleocapsid assembly

AU - Dykeman, Eric Charles

AU - Bingham, Richard John

AU - Weiss, Eva Ursula

AU - Twarock, Reidun

N1 - © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2017/6/19

Y1 - 2017/6/19

N2 - Formation of the hepatitis B virus nucleocapsid is an essential step in the viral lifecycle, but its assembly is not fully understood. We report the discovery of sequence-specific interactions between the viral pre-genome and the hepatitis B core protein that play roles in defining the nucleocapsid assembly pathway. Using RNA SELEX and bioinformatics, we identified multiple regions in the pre-genomic RNA with high affinity for core protein dimers. These RNAs form stem-loops with a conserved loop motif that trigger sequence-specific assembly of virus-like particles (VLPs) at much higher fidelity and yield than in the absence of RNA. The RNA oligos do not interact with preformed RNA-free VLPs, so their effects must occur during particle assembly. Asymmetric cryo-electron microscopy reconstruction of the T = 4 VLPs assembled in the presence of one of the RNAs reveals a unique internal feature connected to the main core protein shell via lobes of density. Biophysical assays suggest that this is a complex involving several RNA oligos interacting with the C-terminal arginine-rich domains of core protein. These core protein–RNA contacts may play one or more roles in regulating the organization of the pre-genome during nucleocapsid assembly, facilitating subsequent reverse transcription and acting as a nucleation complex for nucleocapsid assembly.

AB - Formation of the hepatitis B virus nucleocapsid is an essential step in the viral lifecycle, but its assembly is not fully understood. We report the discovery of sequence-specific interactions between the viral pre-genome and the hepatitis B core protein that play roles in defining the nucleocapsid assembly pathway. Using RNA SELEX and bioinformatics, we identified multiple regions in the pre-genomic RNA with high affinity for core protein dimers. These RNAs form stem-loops with a conserved loop motif that trigger sequence-specific assembly of virus-like particles (VLPs) at much higher fidelity and yield than in the absence of RNA. The RNA oligos do not interact with preformed RNA-free VLPs, so their effects must occur during particle assembly. Asymmetric cryo-electron microscopy reconstruction of the T = 4 VLPs assembled in the presence of one of the RNAs reveals a unique internal feature connected to the main core protein shell via lobes of density. Biophysical assays suggest that this is a complex involving several RNA oligos interacting with the C-terminal arginine-rich domains of core protein. These core protein–RNA contacts may play one or more roles in regulating the organization of the pre-genome during nucleocapsid assembly, facilitating subsequent reverse transcription and acting as a nucleation complex for nucleocapsid assembly.

U2 - 10.1038/nmicrobiol.2017.98

DO - 10.1038/nmicrobiol.2017.98

M3 - Article

SN - 1740-1526

VL - 2

JO - Nature reviews. Microbiology

JF - Nature reviews. Microbiology

M1 - 17098

ER -