''Enterobacteria phage P4'' (also known as satellite phage P4) is a temperate

bacteriophage A bacteriophage (), also known informally as a phage (), is a virus that infects and replicates within bacteria. The term is derived . Bacteriophages are composed of proteins that Capsid, encapsulate a DNA or RNA genome, and may have structu ...

strain of species '' Escherichia virus P2'' within genus '' Peduovirus'' (formerly ''P2-like viruses'', ''P2virus'', and ''P2likevirus''), subfamily ''

Peduovirinae ''Peduoviridae'' is a family of viruses in the class ''Caudoviricetes''. It was previously treated as a subfamily of the morphology based family ''Myoviridae'', which has been found to be paraphyletic and is no longer recognised. Bacteria serve ...

'', family ''

Myoviridae ''Myoviridae'' was a family of bacteriophages in the order '' Caudovirales''. The family ''Myoviridae'' and order '' Caudovirales'' have now been abolished, with the term myovirus now used to refer to the morphology of viruses in this former famil ...

''. It is a

satellite virus A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major groups: satellite viruses and satellite nucleic acids. Satellite viruses, which are ...

, requiring P2-related helper phage to grow lytically.

Structure

The P4 virion has a tail and an icosahedral head containing a linear double-stranded DNA

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

of 11,627 kb.

Life cycle

Phage P4 infects ''

Escherichia coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly fo ...

''. It is a

which cannot engage in lytic growth without the presence of a P2-related helper phage. It generally follows a

lysogenic Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a cir ...

life cycle: after infection, the P4 genome integrates into that of its host. The P4 genome can also exist on its own within the host cell and can replicate as a free

plasmid A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and ...

References

External links

NCBI Taxonomy
Myoviridae Satellite viruses {{virus-stub