Iyer Lakshminarayan M, Abhiman Saraswathi, Aravind L
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
Biol Direct. 2008 Oct 4;3:39. doi: 10.1186/1745-6150-3-39.
Using sequence profile methods and structural comparisons we characterize a previously unknown family of nucleic acid polymerases in a group of mobile elements from genomes of diverse bacteria, an algal plastid and certain DNA viruses, including the recently reported Sputnik virus. Using contextual information from domain architectures and gene-neighborhoods we present evidence that they are likely to possess both primase and DNA polymerase activity, comparable to the previously reported prim-pol proteins. These newly identified polymerases help in defining the minimal functional core of superfamily A DNA polymerases and related RNA polymerases. Thus, they provide a framework to understand the emergence of both DNA and RNA polymerization activity in this class of enzymes. They also provide evidence that enigmatic DNA viruses, such as Sputnik, might have emerged from mobile elements coding these polymerases.
利用序列谱方法和结构比较，我们在来自不同细菌、藻类质体和某些DNA病毒（包括最近报道的“斯普特尼克”病毒）基因组的一组移动元件中，鉴定出一个以前未知的核酸聚合酶家族。利用来自结构域结构和基因邻域的上下文信息，我们提供证据表明，它们可能同时具有引发酶和DNA聚合酶活性，这与之前报道的引发-聚合酶蛋白相当。这些新鉴定的聚合酶有助于定义超家族A DNA聚合酶和相关RNA聚合酶的最小功能核心。因此，它们为理解这类酶中DNA和RNA聚合活性的出现提供了一个框架。它们还提供了证据，表明像“斯普特尼克”这样神秘的DNA病毒可能起源于编码这些聚合酶的移动元件。
