Iverson Eric, Stedman Kenneth
Biology Department, Center for Life in Extreme Environments, Portland State University, Portland, OR, USA.
Front Microbiol. 2012 Jun 5;3:200. doi: 10.3389/fmicb.2012.00200. eCollection 2012.
Viruses of thermophilic Archaea are unique in both their structures and genomic sequences. The most widespread and arguably best studied are the lemon-shaped fuselloviruses. The spindle-shaped virus morphology is unique to Archaea but widespread therein. The best studied fusellovirus is SSV1 from Beppu, Japan, which infects Sulfolobus solfataricus. Very little is known about the function of the genes in the SSV1 genome. Recently we have developed genetic tools to analyze these genes. In this study, we have deleted three SSV1 open reading frames (ORFs) ranging from completely conserved to poorly conserved: VP2, d244, and b129. Deletion of the universally conserved ORF b129, which encodes a predicted transcriptional regulator, results in loss of infectivity. Deletion of the poorly conserved predicted DNA-binding protein gene VP2 yields viable virus that is indistinguishable from wild-type. Deletion of the well-conserved ORF d244 that encodes a predicted nuclease yields viable virus. However, infection of S. solfataricus with virus lacking ORF d244 dramatically retards host growth, compared to the wild-type virus.
嗜热古菌病毒在结构和基因组序列上都很独特。分布最广泛且可能研究得最透彻的是柠檬形的丝状病毒。纺锤形病毒形态是古菌所特有的，且在古菌中广泛存在。研究得最深入的丝状病毒是来自日本别府的SSV1，它感染嗜热栖热菌。人们对SSV1基因组中基因的功能知之甚少。最近我们开发了遗传工具来分析这些基因。在本研究中，我们删除了三个SSV1开放阅读框（ORF），其保守程度从完全保守到保守性较差：VP2、d244和b129。删除普遍保守的ORF b129（其编码一个预测的转录调节因子）会导致感染性丧失。删除保守性较差的预测DNA结合蛋白基因VP2会产生与野生型无法区分的有活力病毒。删除编码预测核酸酶的保守性良好的ORF d244会产生有活力病毒。然而，与野生型病毒相比，用缺乏ORF d244的病毒感染嗜热栖热菌会显著延迟宿主生长。
