EVOLUTION OF AVIAN CORONAVIRUS IBV - SEQUENCE OF THE MATRIX GLYCOPROTEIN GENE AND INTERGENIC REGION OF SEVERAL SEROTYPES
EVOLUTION OF AVIAN CORONAVIRUS IBV - SEQUENCE OF THE MATRIX GLYCOPROTEIN GENE AND INTERGENIC REGION OF SEVERAL SEROTYPES
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DOI：
10.1099/0022-1317-69-3-621
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发表时间：
1988-03-01
影响因子：
3.8
通讯作者：
DAVIS, PJ
中科院分区：
文献类型：
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作者：
CAVANAGH, D;DAVIS, PJ
我们测定了代表A（D207）、B（D3896）、C（D3128）、D（D212）、马萨诸塞州（Mass）、UK 11和UK 12血清型的23株传染性支气管炎病毒（IBV）的基质（M）糖蛋白基因的200 - 240个碱基。检查的碱基编码M的外部亲水区域和第一个膜包埋的疏水区域，这两个区域均包含约20个氨基酸。如蛋白质Mr研究所预测的，A/D和B/C血清型分别具有两个和一个潜在的糖基化位点。这种变异似乎来自碱基取代和缺失/插入的组合。糖基化序列Asn-Cys-Thr高度保守。总体而言，暴露的部分M表现出四倍的氨基酸变异程度比膜嵌入序列。5 ''基因间区域的转录相关同源区序列（CUUAACAA）在所有菌株中均相同，但其位置存在相当大的差异。UK 12的M基因似乎是从一个群体进化而来的。UK 11株通过两个阶段的过程，在基因间区进行碱基替换，产生一个新的AUG翻译起始密码子，随后删除原来的AUG。UK 11株在基因间区与Mass株非常相似，但在蛋白质编码区与所有菌株都不同。血清型B和C的M序列相同，而A和D血清型的M序列非常相似。这些结果进行了讨论，最近的一些菌株的刺突糖蛋白基因的部分测序和发现在体外重组的小鼠肝炎冠状病毒。
We have sequenced 200 to 240 bases of the matrix (M) glycoprotein gene of 23 strains of infectious bronchitis virus (IBV) representing the A (D207), B (D3896), C (D3128), D (D212), Massachusetts (Mass), UK11 and UK12 serotypes. The bases examined code for the external, hydrophilic region and the first membrane-embedded hydrophobic region of M, both regions comprising approximately 20 amino acids. As predicted from protein Mr studies the A/D and B/C serotypes had two and one potential glycosylation sites respectively. This variation appeared to derive from a combination of base substitutions and deletions/insertions. The glycosylation sequence Asn-Cys-Thr was highly conserved. Overall, the exposed part of M exhibited a fourfold greater extent of amino acid variation than did the membrane-embedded sequence. The transcription-associated homology region sequence (CUUAACAA) in the 5'' intergenic region was identical in all strains but there was considerable variation as to its location. The M gene of UK12 appeared to have evolved from a group. A-like M gene by a two stage process involving a base substitution in the intergenic region which generated a new AUG translation start codon followed by deletion of the original AUG. Isolate UK11 closely resembled Mass strains in the intergenic region but was dissimilar from all strains in the protein coding region. The M sequences of serotypes B and C were identical and those of the A and D serotypes very similar. These results are discussed in relation to recent sequencing of part of the spike glycoprotein gene of some of these strains and the discovery of in vitro recombination of murine hepatitis coronavirus.