Daimon Katsuya, Ishino Sonoko, Imai Namiko, Nagumo Sachiyo, Yamagami Takeshi, Matsukawa Hiroaki, Ishino Yoshizumi
Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
Front Mol Biosci. 2018 Apr 16;5:37. doi: 10.3389/fmolb.2018.00037. eCollection 2018.
Living organisms are divided into three domains, Bacteria, Eukarya, and Archaea. Comparative studies in the three domains have provided useful information to understand the evolution of the DNA replication machinery. DNA polymerase is the central enzyme of DNA replication. The presence of multiple family B DNA polymerases is unique in Crenarchaeota, as compared with other archaeal phyla, which have a single enzyme each for family B (PolB) and family D (PolD). We analyzed PolB1 and PolB3 in the hyperthermophilic crenarchaeon, , and found that they are larger proteins than those predicted from the coding regions in our previous study and from public database annotations. The recombinant larger PolBs exhibited the same DNA polymerase activities as previously reported. However, the larger PolB3 showed remarkably higher thermostability, which made this enzyme applicable to PCR. In addition, the high tolerance to salt and heparin suggests that PolB3 will be useful for amplification from the samples with contaminants, and therefore it has a great potential for diagnostic use in the medical and environmental field.
细菌、真核生物和古菌。对这三个域的比较研究为理解DNA复制机制的进化提供了有用信息。DNA聚合酶是DNA复制的核心酶。与其他古菌门相比，泉古菌门中存在多种B族DNA聚合酶是其独特之处，其他古菌门中B族（PolB）和D族（PolD）各只有一种酶。我们分析了嗜热泉古菌中的PolB1和PolB3，发现它们比我们之前研究中根据编码区预测的以及公共数据库注释中的蛋白质更大。重组的更大的PolB表现出与先前报道相同的DNA聚合酶活性。然而，更大的PolB3显示出显著更高的热稳定性，这使得这种酶适用于PCR。此外，对盐和肝素的高耐受性表明PolB3将有助于从含有污染物的样本中进行扩增，因此它在医学和环境领域的诊断应用中具有巨大潜力。
