Contursi Patrizia, Jensen Susanne, Aucelli Tiziana, Rossi Mosé, Bartolucci Simonetta, She Qunxin
Department of Biological Chemistry, Institute of Molecular Biology and Physiology, University of Copenhagen, Copenhagen, Denmark.
Extremophiles. 2006 Dec;10(6):615-27. doi: 10.1007/s00792-006-0017-2. Epub 2006 Aug 3.
The Sulfolobus spindle virus, SSV2, encodes a tyrosine integrase which furthers provirus formation in host chromosomes. Consistently with the prediction made during sequence analysis, integration was found to occur in the downstream half of the tRNA(Gly) (CCC) gene. In this paper we report the findings of a comparative study of SSV2 physiology in the natural host, Sulfolobus islandicus REY15/4, versus the foreign host, Sulfolobus solfataricus, and provide evidence of differently regulated SSV2 life cycles in the two hosts. In fact, whereas a significant induction of SSV2 replication takes place during the growth of the natural host REY15/4, the cellular content of SSV2 DNA remains fairly low throughout the incubation of the foreign host. The accumulation of episomal DNA in the former case cannot be traced to decreased packaging activity because of a simultaneous increase in the virus titre in the medium. In addition, the interaction between SSV2 and its natural host is characterized by the concurrence of host growth inhibition and the induction of viral DNA replication. When this virus-host interaction was investigated using S. islandicus REY15A, a strain which is closely related to the natural host, it was found that the SSV2 replication process was induced in the same way as in the natural host REY15/4.
硫磺矿硫化裂片菌纺锤体病毒（SSV2）编码一种酪氨酸整合酶，该酶促进前病毒在宿主染色体中的形成。与序列分析过程中的预测一致，发现整合发生在tRNA（Gly）（CCC）基因下游的一半区域。在本文中，我们报告了对SSV2在天然宿主冰岛硫化叶菌REY15/4与外来宿主嗜热栖热菌中生理学的比较研究结果，并提供了两种宿主中SSV2生命周期受不同调控的证据。事实上，在天然宿主REY15/4生长期间，SSV2复制有显著诱导，而在外来宿主整个培养过程中，SSV2 DNA的细胞含量一直相当低。在前一种情况下，游离DNA的积累不能归因于包装活性降低，因为培养基中病毒滴度同时增加。此外，SSV2与其天然宿主之间的相互作用的特征是宿主生长受到抑制以及病毒DNA复制被诱导。当使用与天然宿主密切相关的菌株冰岛硫化叶菌REY15A研究这种病毒 - 宿主相互作用时，发现SSV2复制过程与在天然宿主REY15/4中一样被诱导。
