RESUMO
Bacteria of the genus Pseudoalteromonas are ubiquitous in the world's oceans. Marine bacteria have been posited to be associated with a major ancient branch of podoviruses related to T7. Yet, although Pseudoalteromonas phages belonging to the Corticoviridae and the Siphoviridae and prophages belonging to the Myoviridae have been reported, no Pseudoalteromonas podovirus was previously known. Here, a new lytic Pseudoalteromonas marina phage, ÏRIO-1, belonging to the Podoviridae was isolated and characterized with respect to morphology, genomic sequence, and biological properties. Its major encoded proteins were distantly similar to those of T7. The most similar previously sequenced viruses were Pseudomonas phage PA11 and Salinivibrio phage CW02. Whereas many elements of the morphology and gene organization of ÏRIO-1 are similar to those of podoviruses broadly related to T7, ÏRIO-1 conspicuously lacked an RNA polymerase gene. Since definitions of a T7 supergroup have included similarity in the DNA polymerase gene, a detailed phylogenetic analysis was conducted, and two major DNA polymerase clades in Autographivirinae and several structural variants of the polA family represented in podoviruses were found. ÏRIO-1 carries an operon similar to that in a few other podoviruses predicted to specify activities related to γ-glutamyl amide linkages and/or unusual peptide bonds. Most growth properties of ÏRIO-1 were typical of T7-like phages, except for a long latent period.
Assuntos
Bacteriófagos/isolamento & purificação , Vírus de DNA/genética , DNA Viral/química , DNA Viral/genética , Genoma Viral , Pseudoalteromonas/virologia , Água do Mar/virologia , Bacteriófagos/genética , Bacteriófagos/fisiologia , Bacteriófagos/ultraestrutura , Vírus de DNA/isolamento & purificação , Ordem dos Genes , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Filogenia , Podoviridae/genética , Podoviridae/isolamento & purificação , Podoviridae/fisiologia , Podoviridae/ultraestrutura , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Proteínas Virais/genéticaRESUMO
The Sulfitobacter bacteria are ubiquitous and important players in organic sulfur cycling in marine environments. Here, we report the complete genome sequence of ÏGT1 infecting Sulfitobacter sp. HGT1, both of which were isolated from coastal sediment. ÏGT1 has a 40,019-bp genome containing 69 predicted protein-encoding genes.