Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
Environ Microbiol. 2009 Nov;11(11):2821-39. doi: 10.1111/j.1462-2920.2009.01991.x. Epub 2009 Jul 23.
Ostreococcus tauri virus (OtV-1) is a large double-stranded DNA virus and a prospective member of the family Phycodnaviridae, genus Prasinovirus. OtV-1 infects the unicellular marine green alga O. tauri, the smallest known free-living eukaryote. Here we present the 191 761 base pair genome sequence of OtV-1, which has 232 putative protein-encoding and 4 tRNA-encoding genes. Approximately 31% of the viral gene products exhibit a similarity to proteins of known functions in public databases. These include a variety of unexpected genes, for example, a PhoH-like protein, a N-myristoyltransferase, a 3-dehydroquinate synthase, a number of glycosyltransferases and methyltransferases, a prolyl 4-hydroxylase, 6-phosphofructokinase and a total of 8 capsid proteins. A total of 11 predicted genes share homology with genes found in the Ostreococcus host genome. In addition, an intein was identified in the DNA polymerase gene of OtV-1. This is the first report of an intein in the genome of a virus that infects O. tauri. Fifteen core genes common to nuclear-cytoplasmic large dsDNA virus (NCLDV) genomes were identified in the OtV-1 genome. This new sequence data may help to redefine the classification of the core genes of these viruses and shed new light on their evolutionary history.
微拟球藻病毒（OtV-1）是一种大型双链 DNA 病毒，是 Phycodnaviridae 科、Prasinovirus 属的潜在成员。OtV-1 感染单细胞海洋绿藻微拟球藻，这是已知的最小自由生活真核生物。在这里，我们展示了 OtV-1 的 191761 碱基对基因组序列，其中有 232 个可能的蛋白编码基因和 4 个 tRNA 编码基因。大约 31%的病毒基因产物与公共数据库中已知功能的蛋白具有相似性。这些包括各种意想不到的基因，例如 PhoH 样蛋白、N-豆蔻酰转移酶、3-脱氢奎宁酸合酶、多种糖基转移酶和甲基转移酶、脯氨酰 4-羟化酶、6-磷酸果糖激酶和总共 8 种衣壳蛋白。11 个预测基因与在微拟球藻宿主基因组中发现的基因具有同源性。此外，OtV-1 的 DNA 聚合酶基因中鉴定出一个内含子。这是首例在感染微拟球藻的病毒基因组中发现内含子的报道。OtV-1 基因组中鉴定出了 15 个核质大 dsDNA 病毒（NCLDV）基因组的核心基因。这些新的序列数据可能有助于重新定义这些病毒核心基因的分类，并为它们的进化历史提供新的认识。
