A jumbo phage infecting the phytopathogen Ralstonia solanacearum defines a new lineage of the Myoviridae family.
phiRSL1 is a jumbo myovirus stably and lytically infecting the phytopathogenic bacterium Ralstonia solanacearum. In this study, we investigate the infection cycle of varphiRSL1 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, varphiRSL1 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 varphiRSL1 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.
Yamada
Takashi
T
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan. tayamad@hiroshima-u.ac.jp
Satoh
Souichi
S
Ishikawa
Hiroki
H
Fujiwara
Akiko
A
Kawasaki
Takeru
T
Fujie
Makoto
M
Ogata
Hiroyuki
H
D000595:Amino Acid Sequence; D004261:DNA Replication / Q000502:physiology; D004279:DNA, Viral / Q000235:genetics / Q000502:physiology; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D008969:Molecular Sequence Data; D017900:Myoviridae / Q000145:classification* / Q000302:isolation & purification*; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D043368:Ralstonia solanacearum / Q000821:virology*; D014158:Transcription, Genetic
D004279:DNA, Viral; D004259:DNA-Directed DNA Polymerase