Lipps Georg, Röther Susanne, Hart Christina, Krauss Gerhard
Department of Biochemistry, University of Bayreuth, Universitätsstrasse 30, Germany.
EMBO J. 2003 May 15;22(10):2516-25. doi: 10.1093/emboj/cdg246.
Although DNA replication is a process common in all domains of life, primase and replicative DNA polymerase appear to have evolved independently in the bacterial domain versus the archaeal/eukaryal branch of life. Here, we report on a new type of replication protein that constitutes the first member of the DNA polymerase family E. The protein ORF904, encoded by the plasmid pRN1 from the thermoacidophile archaeon Sulfolobus islandicus, is a highly compact multifunctional enzyme with ATPase, primase and DNA polymerase activity. Recombinant purified ORF904 hydrolyses ATP in a DNA-dependent manner. Deoxynucleotides are preferentially used for the synthesis of primers approximately 8 nucleotides long. The DNA polymerase activity of ORF904 synthesizes replication products of up to several thousand nucleotides in length. The primase and DNA polymerase activity are located in the N-terminal half of the protein, which does not show homology to any known DNA polymerase or primase. ORF904 constitutes a new type of replication enzyme, which could have evolved independently from the eubacterial and archaeal/eukaryal proteins of DNA replication.
尽管DNA复制是生命所有领域中常见的过程，但引发酶和复制性DNA聚合酶似乎在细菌领域与古菌/真核生物生命分支中独立进化。在此，我们报道了一种新型复制蛋白，它是DNA聚合酶E家族的首个成员。由嗜热嗜酸古菌冰岛硫化叶菌的质粒pRN1编码的蛋白ORF904是一种高度紧凑的多功能酶，具有ATP酶、引发酶和DNA聚合酶活性。重组纯化的ORF904以依赖DNA的方式水解ATP。脱氧核苷酸优先用于合成约8个核苷酸长的引物。ORF904的DNA聚合酶活性可合成长度达数千个核苷酸的复制产物。引发酶和DNA聚合酶活性位于该蛋白的N端一半区域，该区域与任何已知的DNA聚合酶或引发酶均无同源性。ORF904构成了一种新型复制酶，它可能是从DNA复制的真细菌和古菌/真核生物蛋白独立进化而来的。
