N4-like viruses

The N4-like viruses are bacteriophages within the Podoviridae family.^[1]

Bacteriophage N4 is type species for this genus and was originally isolated from sewers in Genoa, Italy and is active against Escherichia coli K-12. Recently, a number of genomically related phages were isolated, infecting Silicibacter and Sulfitobacter (DSS3ɸ2 and EE36ɸ1)^[2] as well as a number of Pseudomonas phages (LUZ7, LIT1 and PEV2)^[3]

Virology

The virus's virion have icosahedral heads ~70 nm and short tails 10 nm, and contain short fibers originating from the junction between the head and tail. All the phages of this genus are strictly virulent and contain a linear dsDNA genome (with terminal repeats) in the range of 70-75kb.

Molecular biology

A remarkable feature of this clade of phages is the use of three distinct RNA polymerases during its infection cycle. A giant virion-encapsulated RNAP polymerase which is co-injected (early transcription), a heterodimeric phage RNA polymerase (middle region) and the host RNA polymerase (recognizes late promoters).^[4]

References

1. ^ Lavigne, R.; Seto, D.; Mahadevan, P.; Ackermann, H. W.; Kropinski, A. M. (2008). "Unifying classical and molecular taxonomic classification: analysis of the Podoviridae using BLASTP-based tools". Research in Microbiology 159 (5): 406. doi:10.1016/j.resmic.2008.03.005. PMID 18555669.  edit
2. ^ Zhao, Y.; Wang, K.; Jiao, N.; Chen, F. (2009). "Genome sequences of two novel phages infecting marine roseobacters". Environmental Microbiology 11 (8): 2055. doi:10.1111/j.1462-2920.2009.01927.x. PMC 2784036. PMID 19689706. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2784036.  edit
3. ^ Ceyssens, P. J.; Brabban, A.; Rogge, L.; Lewis, M. S.; Pickard, D.; Goulding, D.; Dougan, G.; Noben, J. P. et al. (2010). "Molecular and physiological analysis of three Pseudomonas aeruginosa phages belonging to the “N4-like viruses”". Virology 405 (1): 26. doi:10.1016/j.virol.2010.06.011. PMID 20619867.  edit.
4. ^ Choi, K.; McPartland, J.; Kaganman, I.; Bowman, V.; Rothmandenes, L.; Rossmann, M. (2008). "Insight into DNA and Protein Transport in Double-Stranded DNA Viruses: the Structure of Bacteriophage N4". Journal of Molecular Biology 378 (3): 726. doi:10.1016/j.jmb.2008.02.059. PMC 2396777. PMID 18374942. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2396777.  edit