A jumbo phage infecting the phytopathogen Ralstonia solanacearum defines a new lineage of the Myoviridae family

• Published in: Virology (New York, N.Y.) Vol. 398; no. 1; pp. 135 - 147
• Main Authors: Yamada, Takashi, Satoh, Souichi, Ishikawa, Hiroki, Fujiwara, Akiko, Kawasaki, Takeru, Fujie, Makoto, Ogata, Hiroyuki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2010
• Subjects: Amino Acid Sequence; bacteriophages; carbohydrate metabolism; DNA replication; DNA Replication - physiology; DNA, Viral - genetics; DNA, Viral - physiology; DNA-directed DNA polymerase; DNA-Directed DNA Polymerase - genetics; DNA-Directed DNA Polymerase - metabolism; Gene expression; gene expression regulation; Gene Expression Regulation, Viral; Genome, Viral; Genomic analysis; genomics; homospermidine synthase; Infectious Disease; Jumbo bacteriophage; Molecular Sequence Data; Myoviridae; Myoviridae - classification; Myoviridae - isolation & purification; Myovirus; Oligonucleotide Array Sequence Analysis; open reading frames; pathogenesis; Phylogeny; plant pathogenic bacteria; Proteomic analysis; proteomics; Ralstonia solanacearum; Ralstonia solanacearum - virology; transcription (genetics); Transcription, Genetic; transcriptomics; Proteomic analysis; Genomic analysis; Ralstonia solanacearum; Gene expression; Jumbo bacteriophage
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2009.11.043

Abstract ϕRSL1 is a jumbo myovirus stably and lytically infecting the phytopathogenic bacterium Ralstonia solanacearum . In this study, we investigate the infection cycle of ϕRSL1 and provide a genomic, proteomic and transcriptomic view of this phage. Its 231-kbp genome sequence showed many genes lacking detectable homologs in the current databases and was vastly different from previously studied phage genomes. In addition to these orphan proteins, ϕRSL1 was found to encode several enzymes that are unique among known viruses. These include enzymes for the salvage pathway of NAD+ and for the biosynthetic pathways of lipid, carbohydrate and homospermidine. A chitinase-like protein was found to be a potential lysis enzyme. Our proteomics analysis suggests that ϕRSL1 virions contain at least 25 distinct proteins. We identified six of them including a tail sheath protein and a topoisomerase IB by N-terminal sequencing. Based on a DNA microarray analysis, we identified two transcription patterns.