4株SARS冠状病毒中国分离株3′非编码区的序列测定及分析

分别对 4株SARS冠状病毒中国株基因组 3′非编码区序列进行测定和分析 ,然后应用Blast、DNAstarGeneQuest等软件对中国株的这段序列与其它SARS和非SARS冠状病毒的序列进行比较 .结果显示 ,所测 4株SARS冠状病毒中国分离株的 3′非编码区长度均为 339nt,与其它已测序SARS冠状病毒的相应序列完全一致 .SARS冠状病毒的非编码区含有冠状病毒保守的“伪结”结构 .在距末端 138nt处还存在 1个长约 32nt的Ⅱ型茎 环结构的序列 ,该序列在其它已知人冠状病毒中并不存在 ,而与禽传染性支气管炎病毒和星状病毒中的对应序列高度同源 .

Determination and Analysis of 3′ Untranslated Regions of 4 Strains of SARS Coronavirus Isolated in China

3′untranslated regions (UTRs) of severe acute respiratory syndrom(SARS) coronavirus (SARS CoVs) were amplified from SARS infected Vero E6 cells by RT PCR. The cDNA fragments were sequenced and then analyzed by Blast and DNAstar GeneQuest software. The results showed that the length of 3′ UTRs of four Chinese SARS CoVs was 339 nt, and the sequences of 3′ UTR were the same as those of SARS CoVs isolated in other countries. A pseudoknot structure conserved in coronavirus was contained in the 3′ UTRs of Chinese SARS CoV strain. A stem loop Ⅱ like motif (s2m) with the length of 32 nt, which was conserved in avian infectious bronchitis virus and astrovirus, was also contained in 3′ UTR of SARS CoV, while the motif did not exit in other known human coronaviruses.