| Title |
Genomic characterization of cyanophage vB_AphaS-CL131 infecting filamentous diazotrophic cyanobacterium aphanizomenon flos-aquae reveals novel insights into virus-bacterium interactions / |
| Authors |
Šulčius, Sigitas ; Šimoliūnas, Eugenijus ; Alzbutas, Gediminas ; Gasiūnas, Giedrius ; Jauniškis, Vykintas ; Kuznecova, Jolita ; Miettinen, Sini ; Nilsson, Emelie ; Meškys, Rolandas ; Roine, Elina ; Paškauskas, Ričardas ; Holmfeldt, Karin |
| DOI |
10.1128/AEM.01311-18 |
| Full Text |
|
| Is Part of |
Applied and environmental microbiology.. Washington : American Society for Microbiology. 2019, vol. 85, no 1, e01311-18, p. 1-48.. ISSN 0099-2240. eISSN 1098-5336 |
| Keywords [eng] |
Baltic Sea ; brackish environment ; phage-encoded CRISPR-Cas ; Siphoviridae ; TA system |
| Abstract [eng] |
While filamentous cyanobacteria play a crucial role in food web dynamics and biogeochemical cycling of many aquatic ecosystems around the globe, the knowledge regarding the phages infecting them is limited. Here, we describe the complete genome of the virulent cyanophage vB_AphaS-CL131 (here, CL 131), a Siphoviridae phage that infects the filamentous diazotrophic bloom-forming cyanobacterium Aphanizomenon flos-aquae in the brackish Baltic Sea. CL 131 features a 112,793-bp double-stranded DNA (dsDNA) genome encompassing 149 putative open reading frames (ORFs), of which the majority (86%) lack sequence homology to genes with known functions in other bacteriophages or bacteria. Phylogenetic analysis revealed that CL 131 possibly represents a new evolutionary lineage within the group of cyanophages infecting filamentous cyanobacteria, which form a separate cluster from phages infecting unicellular cyanobacteria. CL 131 encodes a putative type V-U2 CRISPR-Cas system with one spacer (out of 10) targeting a DNA primase pseudogene in a cyanobacterium and a putative type II toxin-antitoxin system, consisting of a GNAT family N-acetyltransferase and a protein of unknown function containing the PRK09726 domain (characteristic of HipB antitoxins). Comparison of CL 131 proteins to reads from Baltic Sea and other available fresh- and brackish-water metagenomes and analysis of CRISPR-Cas arrays in publicly available A. flos-aquae genomes demonstrated that phages similar to CL 131 are present and dynamic in the Baltic Sea and share a common history with their hosts dating back at least several decades. In addition, different CRISPR-Cas systems within individual A. flos-aquae genomes targeted several sequences in the CL 131 genome, including genes related to virion structure and morphogenesis. Altogether, these findings revealed new genomic information for exploring viral diversity and provide a model system for investigation of virus-host interactions in filamentous cyanobacteria. |
| Published |
Washington : American Society for Microbiology |
| Type |
Journal article |
| Language |
English |
| Publication date |
2019 |
| CC license |
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