Identification of a potential new sub family of DNA polymerase in bacteriophages.

Bacteriophages (bacterial viruses) are the most abundant organisms on earth. In order to replicate, bacteriophages hijack and eventually kill bacteria, making them a potential useful tool to treat bacterial infection. They contain the biggest diversity of modified nucleobases observed in nature so far, that prevent them from cleavage by host restriction endonucleases. However, this modified alphabet of nucleobases can make the genome of such bacteriophages resistant to sequencing by commercial polymerases. The discovery of a polymerase capable of reading any type of modified genomic DNA would be a great tool for the knowledge of this hidden viral world. Recently, the bacteriophage YERA41, that infects Yersinia ruckeri bacteria, was isolated. It appears to be an unconventional phage that contains hypermodified thymidine in its genomic DNA, that only the phage DNA polymerase (DNAP) can replicate.