ABSTRACT
A novel siphovirus, vB_PagS_MED16 (MED16) was isolated in Lithuania using Pantoea agglomerans strain BSL for the phage propagation. The double-stranded DNA genome of MED16 (46,103 bp) contains 73 predicted open reading frames (ORFs) encoding proteins, but no tRNA. Our comparative sequence analysis revealed that 26 of these ORFs code for unique proteins that have no reliable identity when compared to database entries. Based on phylogenetic analysis, MED16 represents a new genus with siphovirus morphology. In total, 35 MED16 ORFs were given a putative functional annotation, including those coding for the proteins responsible for virion morphogenesis, phage-host interactions, and DNA metabolism. In addition, a gene encoding a preQ0 DNA deoxyribosyltransferase (DpdA) is present in the genome of MED16 and the LC-MS/MS analysis indicates 2'-deoxy-7-amido-7-deazaguanosine (dADG)-modified phage DNA, which, to our knowledge, has never been experimentally validated in genomes of Pantoea phages. Thus, the data presented in this study provide new information on Pantoea-infecting viruses and offer novel insights into the diversity of DNA modifications in bacteriophages.
Subject(s)
DNA, Viral , Genome, Viral , Guanosine , Open Reading Frames , Pantoea/virology , Siphoviridae , Viral Proteins , DNA, Viral/genetics , DNA, Viral/metabolism , Guanosine/analogs & derivatives , Guanosine/chemistry , Guanosine/metabolism , Siphoviridae/genetics , Siphoviridae/metabolism , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
A cold-adapted siphovirus, vB_PagS_AAS23 (AAS23) was isolated in Lithuania using the Pantoea agglomerans strain AUR for the phage propagation. The double-stranded DNA genome of AAS23 (51,170 bp) contains 92 probable protein encoding genes, and no genes for tRNA. A comparative sequence analysis revealed that 25 of all AAS23 open reading frames (ORFs) code for unique proteins that have no reliable identity to database entries. Based on the phylogenetic analysis, AAS23 has no close relationship to other viruses publicly available to date and represents a single species of the genus Sauletekiovirus within the family Drexlerviridae. The phage is able to form plaques in bacterial lawns even at 4 °C and demonstrates a depolymerase activity. Thus, the data presented in this study not only provides the information on Pantoea-infecting bacteriophages, but also offers novel insights into the diversity of cold-adapted viruses and their potential to be used as biocontrol agents.
