TY - JOUR
T1 - Deciphering the origin and evolution of Hepatitis B viruses by means of a family of non-enveloped fish viruses
AU - Lauber, Chris
AU - Seitz, Stefan
AU - Mattei, Simone
AU - Suh, Alexander
AU - Beck, Jürgen
AU - Herstein, Jennifer
AU - Börold, Jacob
AU - Salzburger, Walter
AU - Kaderali, Lars
AU - Briggs, John A. G.
AU - Bartenschlager, Ralf
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Hepatitis B viruses (HBVs), which are enveloped viruses with reverse-transcribed DNA genomes, constitute the family Hepadnaviridae. An outstanding feature of HBVs is their streamlined genome organization with extensive gene overlap. Remarkably, the ∼1,100 bp open reading frame (ORF) encoding the envelope proteins is fully nested within the ORF of the viral replicase P. Here, we report the discovery of a diversified family of fish viruses, designated nackednaviruses, which lack the envelope protein gene, but otherwise exhibit key characteristics of HBVs including genome replication via protein-primed reverse-transcription and utilization of structurally related capsids. Phylogenetic reconstruction indicates that these two virus families separated more than 400 million years ago before the rise of tetrapods. We show that HBVs are of ancient origin, descending from non-enveloped progenitors in fishes. Their envelope protein gene emerged de novo, leading to a major transition in viral lifestyle, followed by co-evolution with their hosts over geologic eras.
AB - Hepatitis B viruses (HBVs), which are enveloped viruses with reverse-transcribed DNA genomes, constitute the family Hepadnaviridae. An outstanding feature of HBVs is their streamlined genome organization with extensive gene overlap. Remarkably, the ∼1,100 bp open reading frame (ORF) encoding the envelope proteins is fully nested within the ORF of the viral replicase P. Here, we report the discovery of a diversified family of fish viruses, designated nackednaviruses, which lack the envelope protein gene, but otherwise exhibit key characteristics of HBVs including genome replication via protein-primed reverse-transcription and utilization of structurally related capsids. Phylogenetic reconstruction indicates that these two virus families separated more than 400 million years ago before the rise of tetrapods. We show that HBVs are of ancient origin, descending from non-enveloped progenitors in fishes. Their envelope protein gene emerged de novo, leading to a major transition in viral lifestyle, followed by co-evolution with their hosts over geologic eras.
U2 - 10.1016/j.chom.2017.07.019
DO - 10.1016/j.chom.2017.07.019
M3 - Article
VL - 22
SP - 387-399.e6
JO - Cell Host & Microbe
JF - Cell Host & Microbe
SN - 1931-3128
IS - 3
ER -