Abrahão Jônatas, Silva Lorena, Silva Ludmila Santos, Khalil Jacques Yaacoub Bou, Rodrigues Rodrigo, Arantes Thalita, Assis Felipe, Boratto Paulo, Andrade Miguel, Kroon Erna Geessien, Ribeiro Bergmann, Bergier Ivan, Seligmann Herve, Ghigo Eric, Colson Philippe, Levasseur Anthony, Kroemer Guido, Raoult Didier, La Scola Bernard
MEPHI, APHM, IRD 198, Aix Marseille Univ, IHU-Méditerranee Infection, 19-21 Bd Jean Moulin, 13005, Marseille, France.
Laboratório de Vírus, Instituto de Ciências Biológicas, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
Nat Commun. 2018 Feb 27;9(1):749. doi: 10.1038/s41467-018-03168-1.
Here we report the discovery of two Tupanvirus strains, the longest tailed Mimiviridae members isolated in amoebae. Their genomes are 1.44-1.51 Mb linear double-strand DNA coding for 1276-1425 predicted proteins. Tupanviruses share the same ancestors with mimivirus lineages and these giant viruses present the largest translational apparatus within the known virosphere, with up to 70 tRNA, 20 aaRS, 11 factors for all translation steps, and factors related to tRNA/mRNA maturation and ribosome protein modification. Moreover, two sequences with significant similarity to intronic regions of 18 S rRNA genes are encoded by the tupanviruses and highly expressed. In this translation-associated gene set, only the ribosome is lacking. At high multiplicity of infections, tupanvirus is also cytotoxic and causes a severe shutdown of ribosomal RNA and a progressive degradation of the nucleus in host and non-host cells. The analysis of tupanviruses constitutes a new step toward understanding the evolution of giant viruses.
在此，我们报告发现了两种土潘病毒株，它们是在变形虫中分离出的尾最长的拟菌病毒科成员。它们的基因组是1.44 - 1.51兆碱基的线性双链DNA，编码1276 - 1425个预测蛋白。土潘病毒与拟菌病毒谱系有着共同的祖先，这些巨型病毒在已知的病毒圈中拥有最大的翻译装置，有多达70种转运RNA、20种氨酰-tRNA合成酶、11种参与所有翻译步骤的因子，以及与转运RNA/信使RNA成熟和核糖体蛋白修饰相关的因子。此外，土潘病毒编码了两个与18 S核糖体RNA基因内含子区域具有显著相似性的序列，且高表达。在这个与翻译相关的基因集中，仅缺少核糖体。在高感染复数时，土潘病毒也具有细胞毒性，会导致核糖体RNA严重失活，并使宿主细胞和非宿主细胞中的细胞核逐渐降解。对土潘病毒的分析是朝着理解巨型病毒进化迈出的新一步。
