Comparison of four regions in the replicase gene of heterologous infectious bronchitis virus strains.
Comparison of four regions in the replicase gene of heterologous infectious bronchitis virus strains.
复制标题
DOI：
10.1016/j.virol.2004.03.032
复制
发表时间：
2004-06-20
期刊：
影响因子：
3.7
通讯作者：
Cardona CJ
中科院分区：
文献类型：
--
作者：
Mondal SP;Cardona CJ
传染性支气管炎病毒（IBV）产生6个亚基因组（sg）mRNAs，每个sg mRNAs含有64个核苷酸（nt）的前导序列，通过不连续的过程从基因组的5′端衍生。几个推定的功能结构域，如木瓜蛋白酶样蛋白酶（PLpro），主要蛋白酶（Mpro），RNA依赖性RNA聚合酶（RdRp）和RNA解旋酶的复制酶基因编码的病毒复制是重要的。我们测定了20个异源IBV株复制酶基因5′-末端序列PLpro、Mpro和RdRp的4个区域，并与已发表的冠状病毒序列进行了比较。所有冠状病毒5′-末端和PLpro结构域都是不同的，而Mpro和RdRp结构域则高度保守，分别有28%和48%的保守残基。在IBV毒株中，包括前导序列在内的5′端非翻译区高度保守（>94%），而N端编码区和PLpro结构域高度变异，同源性分别为84.6%~ 100%和77.6%~ 100%。IBV Mpro和RdRp结构域高度保守，保守性分别为82.7%和92.7%。BJ株与其他IBV在复制酶的所有四个区域中差异最大。基于复制酶基因的系统发育聚类与基于抗原的冠状病毒三组分类相同。然而，基于复制酶基因结构域的IBV毒株分类与型特异性抗原组没有相关性。从感染鸡中回收的许多IBV的复制酶基因序列与疫苗病毒的复制酶基因序列相同，无论血清型如何，这表明疫苗和田间分离株之间存在遗传物质的交换，或者存在向特定复制酶基因型的趋同进化。复制酶基因各区域的基因型与致病型之间均无相关性，提示复制酶不是IBV致病性的唯一决定因素。
Infectious bronchitis virus (IBV) produces six subgenomic (sg) mRNAs, each containing a 64 nucleotide (nt) leader sequence, derived from the 5′ end of the genome by a discontinuous process. Several putative functional domains such as a papain-like proteinase (PLpro), main protease (Mpro), RNA-dependent RNA polymerase (RdRp), and RNA helicase encoded by the replicase gene are important for virus replication. We have sequenced four regions of the replicase genes corresponding to the 5′-terminal sequence, PLpro, Mpro, and RdRp domains from 20 heterologous IBV strains, and compared them with previously published coronavirus sequences. All the coronavirus 5′-termini and PLpro domains were divergent, unlike the Mpro and the RdRp domains that were highly conserved with 28% and 48% conserved residues, respectively. Among IBV strains, the 5′ untranslated region including the leader sequence was highly conserved (>94% identical); whereas, the N-terminal coding region and the PLpro domains were highly variable ranging from 84.6% to 100%, and 77.6% to 100% identity, respectively. The IBV Mpro and RdRp domains were highly conserved with 82.7% and 92.7% conserved residues, respectively. The BJ strain was the most different from other IBVs in all four regions of the replicase. Phylogeny-based clustering based on replicase genes was identical to the antigen-based classification of coronaviruses into three groups. However, the IBV strain classification based on replicase gene domains did not correlate with that of the type-specific antigenic groups. The replicase gene sequences of many IBVs recovered from infected chickens were identical to those of vaccine viruses irrespective of serotype, suggesting that either there has been an exchange of genetic material among vaccine and field isolates or that there is a convergent evolution to a specific replicase genotype. There was no correlation between the genotype of any region of the replicase gene and pathotype, suggesting that the replicase is not the sole determinant of IBV pathogenicity.
登录
查看更多内容
DOI：
10.1074/jbc.274.21.14918
发表时间：
1999-05-21
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Herold J;Siddell SG;Gorbalenya AE
通讯作者：
Gorbalenya AE
影响因子：
3.8
作者：
Hegyi, A;Ziebuhr, J
通讯作者：
Ziebuhr, J
影响因子：
2.7
作者：
González JM;Gomez-Puertas P;Cavanagh D;Gorbalenya AE;Enjuanes L
通讯作者：
Enjuanes L
影响因子：
3.8
作者：
Chouljenko, VN;Lin, XQ;Gorbalenya, AE
通讯作者：
Gorbalenya, AE
影响因子：
3.7
作者：
HEROLD, J;RAABE, T;SIDDELL, SG
通讯作者：
SIDDELL, SG