Grass carp reovirus (GCRV) is a relatively new virus first isolated in China and is a member of the Aquareovirus genus of the Reoviridae family. Recent report of genomic se-quencing showed that GCRV shared high degree...Grass carp reovirus (GCRV) is a relatively new virus first isolated in China and is a member of the Aquareovirus genus of the Reoviridae family. Recent report of genomic se-quencing showed that GCRV shared high degree of homology with mammalian reovirus (MRV). As a step of our effort to understand the structural basis of GCRV pathogenesis, we determined the three-dimensional (3D) structure of GCRV capsid at 17 ? resolution by electron cryomicro-scopy. Each GCRV capsid has a multilayered organization, consisting of an RNA core, an inner, middle and outer protein layer. The outer layer is made up of 200 trimers that are arranged on an incomplete T=13 icosahedral lattice. A characteristic feature of this layer is the depression re-sulting from the absence of trimers around the peripentonal positions, revealing the underlying trimers on the middle layer. There are 120 subunits in the inner layer arranged with T=1 symme-try. These structural features are common to other members of the Reoviridae. Moreover, SDS-PAGE analysis showed that GCRV virions contain seven structural proteins (VP1-VP7). These structural proteins have a high degree of sequence homology to MRV, consistent with the structural similarities observed in our study. The high structural similarities of isolated GCRV and MRV suggest that future structural studies focusing on GCRV entering into and replicating within its host cell are necessary in order to fully understand the structural basis of GCRV pathogenesis.展开更多
Sequence analysis of a new norovirus(NV) isolated from Lanzou city of China was performed based on partial sequence of RNA dependent RNA polymerase(RdRp) and complete capsid protein(VP1) gene.The isolated strain CHN02...Sequence analysis of a new norovirus(NV) isolated from Lanzou city of China was performed based on partial sequence of RNA dependent RNA polymerase(RdRp) and complete capsid protein(VP1) gene.The isolated strain CHN02/LZ35666 shared high sequence homology with GII-4 NVs.Nucleotide homologies of RdRp region and encoded capsid protein region were 90.4%-98.6% and 89.8%-95.7%,respectively,while amino acid homology of capsid protein region was 94.4%-97.4%.The analysis of GDD motif in RdRp region indicated this GDD motif of Lanzhou strain differed from those of the GII-4 predominant epidemic strains.Lanzhou strain formed an independent branch in GII-4 cluster in the phylogenetic tree based on nucleotide sequence of RdRp region and amino acid sequence of capsid protein.Sequence alignment revealed a mutation at the fourth key site of the receptor-binding interface in the strains isolated after 2002 compared with those of previous strains suggesting a possible change of binding pattern to HBGAs receptors.展开更多
猪圆环病毒2型(Porcine circovirus Type 2,PCV2)被认为是猪圆环病毒相关疾病(PCVAD)的主要病原体,分为多个基因型和亚型,具有很高的突变率,给猪场的疫病防控带来了巨大的挑战。虽然PCV2不同基因型间存在一定的交叉免疫保护作用,但是,...猪圆环病毒2型(Porcine circovirus Type 2,PCV2)被认为是猪圆环病毒相关疾病(PCVAD)的主要病原体,分为多个基因型和亚型,具有很高的突变率,给猪场的疫病防控带来了巨大的挑战。虽然PCV2不同基因型间存在一定的交叉免疫保护作用,但是,在国内外多个接种了PCV2疫苗的猪群中,报道分离得到了突变型PCV2d毒株(又称PCV2b-1C,PCV2 mutant或m PCV2b)。为更好地防控PCV2d毒株的流行,文中就PCV2d的分子生物学特征和流行病学情况分别进行了综述。展开更多
基金The research in Dr.Zhou’s lab is supported by NIH(Grant Nos.AI46420&CA94809)the Welch Foundation(AU-1492)+1 种基金 the American Heart Association(Grant No.0240216N)This work was supported by the National Natural Science Foundation of China(Grant Nos.30170730&30470074).
文摘Grass carp reovirus (GCRV) is a relatively new virus first isolated in China and is a member of the Aquareovirus genus of the Reoviridae family. Recent report of genomic se-quencing showed that GCRV shared high degree of homology with mammalian reovirus (MRV). As a step of our effort to understand the structural basis of GCRV pathogenesis, we determined the three-dimensional (3D) structure of GCRV capsid at 17 ? resolution by electron cryomicro-scopy. Each GCRV capsid has a multilayered organization, consisting of an RNA core, an inner, middle and outer protein layer. The outer layer is made up of 200 trimers that are arranged on an incomplete T=13 icosahedral lattice. A characteristic feature of this layer is the depression re-sulting from the absence of trimers around the peripentonal positions, revealing the underlying trimers on the middle layer. There are 120 subunits in the inner layer arranged with T=1 symme-try. These structural features are common to other members of the Reoviridae. Moreover, SDS-PAGE analysis showed that GCRV virions contain seven structural proteins (VP1-VP7). These structural proteins have a high degree of sequence homology to MRV, consistent with the structural similarities observed in our study. The high structural similarities of isolated GCRV and MRV suggest that future structural studies focusing on GCRV entering into and replicating within its host cell are necessary in order to fully understand the structural basis of GCRV pathogenesis.
文摘Sequence analysis of a new norovirus(NV) isolated from Lanzou city of China was performed based on partial sequence of RNA dependent RNA polymerase(RdRp) and complete capsid protein(VP1) gene.The isolated strain CHN02/LZ35666 shared high sequence homology with GII-4 NVs.Nucleotide homologies of RdRp region and encoded capsid protein region were 90.4%-98.6% and 89.8%-95.7%,respectively,while amino acid homology of capsid protein region was 94.4%-97.4%.The analysis of GDD motif in RdRp region indicated this GDD motif of Lanzhou strain differed from those of the GII-4 predominant epidemic strains.Lanzhou strain formed an independent branch in GII-4 cluster in the phylogenetic tree based on nucleotide sequence of RdRp region and amino acid sequence of capsid protein.Sequence alignment revealed a mutation at the fourth key site of the receptor-binding interface in the strains isolated after 2002 compared with those of previous strains suggesting a possible change of binding pattern to HBGAs receptors.
