Genome sequences of two novel phages infecting marine roseobacters
Wang, Kui（Univ Maryland, Ctr Marine Biotechnol, Inst Biotechnol, Baltimore, MD 21202 USA）
Chen, Feng（Univ Maryland, Ctr Marine Biotechnol, Inst Biotechnol, Baltimore, MD 21202 USA）
- 海洋环境－已发表论文 
P>Two bacteriophages, DSS3 Theta 2 and EE36 Theta 1, which infect marine roseobacters Silicibacter pomeroyi DSS-3 and Sulfitobacter sp. EE-36, respectively, were isolated from Baltimore Inner Harbor water. These two roseophages resemble bacteriophage N4, a large, short-tailed phage infecting Escherichia coli K12, in terms of their morphology and genomic structure. The full genome sequences of DSS3 Theta 2 and EE36 Theta 1 reveal that their genome sizes are 74.6 and 73.3 kb, respectively, and they both contain a highly conserved N4-like DNA replication and transcription system. Both roseophages contain a large virion-encapsidated RNA polymerase gene (> 10 kb), which was first discovered in N4. DSS3 Theta 2 and EE36 Theta 1 also possess several genes (i.e. ribonucleotide reductase and thioredoxin) that are most similar to the genes in roseobacters. Overall, the two roseophages are highly closely related, and share 80-94% nucleotide sequence identity over 85% of their ORFs. This is the first report of N4-like phages infecting marine bacteria and the second report of N4-like phage since the discovery of phage N4 40 years ago. The finding of these two N4-like roseophages will allow us to further explore the specific phage-host interaction and evolution for this unique group of bacteriophages.