Jonassen C M, Jonassen T O, Grinde B
Department of Virology, National Institute of Public Health, Oslo, Norway.
J Gen Virol. 1998 Apr;79 ( Pt 4):715-8. doi: 10.1099/0022-1317-79-4-715.
In the 3' non-coding region of the genomes of infectious bronchitis virus, an avian coronavirus and the picornavirus equine rhinovirus serotype 2, there is a motif with remarkable similarity, both in sequence and folding, to the second RNA stem-loop from the 3' end of the genomes of human astroviruses. This motif was also found in astroviruses of sheep, pig and turkey, suggesting that it is a common feature of all astroviruses. The conserved nature of the motif indicates that there has been strong selection for its preservation. There is significant homology between the regions flanking this motif in infectious bronchitis virus and a continuous RNA sequence at the same distance from the 3' poly(A) tail in some related mammalian coronaviruses. These observations suggest that the presence of the motif in these three viral families is the result of at least two separate RNA recombination events.
在传染性支气管炎病毒（一种禽冠状病毒）和小RNA病毒马鼻病毒2型的基因组3'非编码区，存在一个基序，其在序列和折叠方面与人类星状病毒基因组3'端的第二个RNA茎环具有显著相似性。该基序也在绵羊、猪和火鸡的星状病毒中被发现，表明它是所有星状病毒的共同特征。该基序的保守性质表明其保存受到了强烈选择。传染性支气管炎病毒中该基序两侧的区域与一些相关哺乳动物冠状病毒中距3'多聚腺苷酸尾相同距离处的连续RNA序列之间存在显著同源性。这些观察结果表明，这三个病毒家族中该基序的存在是至少两次独立RNA重组事件的结果。
