Zhu, BinWang, LongfeiMitsunobu, HitoshiLu, XuelingHernandez, AlfredoYoshida-Takashima, YukariNunoura, TakuroTabor, StanleyRichardson, Charles2019-10-052017Zhu, Bin, Longfei Wang, Hitoshi Mitsunobu, Xueling Lu, Alfredo J. Hernandez, Yukari Yoshida-Takashima, Takuro Nunoura, Stanley Tabor, and Charles C. Richardson. 2017. “Deep-Sea Vent Phage DNA Polymerase Specifically Initiates DNA Synthesis in the Absence of Primers.” Proceedings of the National Academy of Sciences 114 (12): E2310–18. https://doi.org/10.1073/pnas.1700280114.0027-84240744-28311091-6490http://nrs.harvard.edu/urn-3:HUL.InstRepos:41483349A DNA polymerase is encoded by the deep-sea vent phage NrS-1. NrS-1 has a unique genome organization containing genes that are predicted to encode a helicase and a single-stranded DNA (ssDNA)binding protein. The gene for an unknown protein shares weak homology with the bifunctional primase-polymerases (prim-pols) from archaeal plasmids but is missing the zinc-binding domain typically found in primases. We show that this gene product has efficient DNA polymerase activity and is processive in DNA synthesis in the presence of the NrS-1 helicase and ssDNA-binding protein. Remarkably, this NrS-1 DNA polymerase initiates DNA synthesis from a specific template DNA sequence in the absence of any primer. The de novo DNA polymerase activity resides in the N-terminal domain of the protein, whereas the C-terminal domain enhances DNA binding.en-USJournal Article2019-10-0510.1073/pnas.1700280114