标题: Hepatitis B Virus Genotype G forms core-like particles [打印本页] 作者: liver411 时间: 2010-6-20 14:58 标题: Hepatitis B Virus Genotype G forms core-like particles
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with unique structural properties
J Viral Hepat. 2010 Jun 8. [Epub ahead of print]
Hepatitis B Virus Genotype G forms core-like particles with unique structural
properties.
Viral Diseases Division, National Microbiology Laboratory, Public Health
Agency of Canada, Winnipeg, Manitoba, Canada.
Abstract
Summary. We have determined the structure of the core capsid of an unusual
variant of hepatitis B virus, genotype G (HBV/G) at 14 A resolution, using
cryo-electron microscopy. The structure reveals surface features not present
in the prototype HBV/A genotype. HBV/G is novel in that it has a unique 36- bp
insertion downstream of the core gene start codon. This results in a twelve
amino acid insertion at the N-terminal end of the core protein, and two stop
codons in the precore region that prevent the expression of HBeAg. HBV/G
replication in patients is associated with co-infection with another genotype
of HBV, suggesting that HBV/G may have reduced replication efficiency in vivo.
We localized the N-terminal insertion in HBV/G and show that it forms two
additional masses on the core surface adjacent to each of the dimer-spikes and
have modelled the structure of the additional residues within this density. We
show that the position of the insertion would not interfere with translocation
of nucleic acids through the pores to the core interior compartment. However,
the insertion may partially obscure several residues on the core surface that
are known to play a role in envelopment and secretion of virions, or that
could affect structural rearrangements that may trigger envelopment after DNA
second-strand synthesis.
PMID: 20546498 [PubMed - as supplied by publisher]