摘要
20 0 3年 3月 ,人类发现一种新的冠状病毒SARS CoV ,这种病毒是非典型性肺炎 (SARS)的病原体。SARS CoV的基因组序列已经由包括中国科学家在内的全世界的科研人员测定完成。该文对国际报道的SARS病源的基因序列进行了收录 ,阐述了SARS CoV基因组的基本特性 :SARS CoV的基因组长约 2 8～ 30kb ,与冠状病毒科的基因组长度相符合 ,其中包括 11个编码序列 ,基因组的组织方式也与其他冠状病毒类似 ,从表面蛋白 (S蛋白 )、外膜蛋白 (M蛋白 )和核蛋白 (N蛋白 )上看 ,SARS病毒与其他冠状病毒的对应蛋白进化关系接近。同时发现 ,在某些区域 ,SARS病毒的基因序列与其他冠状病毒存在相当大的差异 ,具有自身比较保守的基因组序列结构。而且氨基酸的序列也与其他冠状病毒有很大程度的不同。基因信息的冗余分析表明 ,SARS CoV具有较低的冗余度 ,即发生变异的可能性比较大。虽然SARS CoV外表与冠状病毒类似 ,亲缘关系未超出冠状病毒科界限 ,但由于蛋白基因与氨基酸的序列与其他冠状病毒有本质不同 ,因此可能不是其他冠状病毒的变异体 ,而是一种与冠状病毒类似、但早已独立存在。
In March 2003,SARS CoV,a novel coronavirus which has been proved to be a pathogen causing Severe Acute Respiratory Syndrome (SARS).The complete genome of SARS CoV has been sequenced by international collaboration including China.In the present study,the genome sequences were collected from NCBI and genomic characterization was analyzed.SARS CoV has a genome of 28～30 kb including 11 ORFs (Open Reading Frames),which is consistent with that of coronavirus family, and its genome organization is similar to those of other coronaviruses as well. SARS CoV evolutionally closes to other coronavirus in their corresponding proteins,such as spike protein,small membrane protein and nucleocapsid protein.In some regions of the genome,the genomic sequence of SARS CoV was significantly different from that of other coronavirus,and has a self conservative genomic sequence.Moreover,its encoding protein sequences were greatly different from those of other coronavirus.The analysis indicated that SARS CoV has lower redundancy,that is,it has a high variation possibility.It may not be a variant of other coronaviruses but a novel coronavirus,which existed independently in nature and was not recognized by human being before,although SARS CoV is morphologically similar to other coronavirus and belongs to coronavirus family.The sequences of its genes and encoding proteins are substantially different from those of other coronavirus.
