Senkevich T G, Koonin E V, Bugert J J, Darai G, Moss B
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Virology. 1997 Jun 23;233(1):19-42. doi: 10.1006/viro.1997.8607.
Analysis of the molluscum contagiosum virus (MCV) genome revealed that it encodes approximately 182 proteins, 105 of which have direct counterparts in orthopoxviruses (OPV). The corresponding OPV proteins comprise those known to be essential for replication as well as many that are still uncharacterized, including 2 of less than 60 amino acids that had not been previously noted. The OPV proteins most highly conserved in MCV are involved in transcription; the least conserved include membrane glycoproteins. Twenty of the MCV proteins with OPV counterparts also have cellular homologs and additional MCV proteins have conserved functional motifs. Of the 77 predicted MCV proteins without OPV counterparts, 10 have similarity to other MCV proteins and/or distant similarity to proteins of other poxviruses and 16 have cellular homologs including some predicted to antagonize host defenses. Clustering poxvirus proteins by sequence similarity revealed 3 unique MCV gene families and 8 families that are conserved in MCV and OPV. Two unique families contain putative membrane receptors; the third includes 2 proteins, each containing 2 DED apoptosis signal transduction domains. Additional families with conserved patterns of cysteines and putative redox active centers were identified. Promoters, transcription termination signals, and DNA concatemer resolution sequences are highly conserved in MCV and OPV. Phylogenetic analysis suggested that MCV, OPV, and leporipoxviruses radiated from a common poxvirus ancestor after the divergence of avipoxviruses. Despite the acquisition of unique genes for host interactions and changes in GC content, the physical order and regulation of essential ancestral poxvirus genes have been largely conserved in MCV and OPV.
对传染性软疣病毒（MCV）基因组的分析显示，它编码约182种蛋白质，其中105种在正痘病毒（OPV）中有直接对应的蛋白质。相应的OPV蛋白质包括那些已知对复制至关重要的蛋白质以及许多仍未被鉴定的蛋白质，其中包括2种少于60个氨基酸的蛋白质，这些蛋白质此前未被注意到。在MCV中保守性最高的OPV蛋白质参与转录；保守性最低的包括膜糖蛋白。20种与OPV对应的MCV蛋白质也有细胞同源物，另外一些MCV蛋白质具有保守的功能基序。在77种预测的无OPV对应物的MCV蛋白质中，10种与其他MCV蛋白质相似和/或与其他痘病毒蛋白质有远缘相似性，16种有细胞同源物，包括一些预测可拮抗宿主防御的蛋白质。通过序列相似性对痘病毒蛋白质进行聚类分析，发现了3个独特的MCV基因家族以及在MCV和OPV中保守的8个家族。两个独特的家族包含推定的膜受体；第三个家族包括2种蛋白质，每种蛋白质含有2个DED凋亡信号转导结构域。还鉴定出了具有保守半胱氨酸模式和推定氧化还原活性中心的其他家族。启动子、转录终止信号和DNA串联体解析序列在MCV和OPV中高度保守。系统发育分析表明，在禽痘病毒分化后，MCV、OPV和兔痘病毒从一个共同的痘病毒祖先分化而来。尽管获得了用于宿主相互作用的独特基因以及GC含量发生了变化，但在MCV和OPV中，基本祖先痘病毒基因的物理顺序和调控在很大程度上得以保留。
