Escherichia virus T5


Bacteriophage T5 is a tailed virus within the family Demerecviridae. This bacteriophage specifically infects E. coli bacterial cells and follows a lytic life cycle.

Structure and genome

The T5 virion includes a 90 nanometer icosahedral capsid and a 160 nanometer-long flexible, non-contractile tail.
The capsid contains the phage's 121,750 base pair, double-stranded DNA genome which is predicted to encode about 162 proteins. The genome has a unique sequence of 111,613 bp with two identical large direct terminal repetitions of 10,139 bp. When the genome sequence was published in 2005, only 61 of the 168 encoded proteins had been assigned functions based on homology to known sequences. More than half of all genes were predicted ORFs lacking similarity to any known proteins.

Infection

Bacteriophage T5 has been shown to infect E. coli after its receptor binding protein, pb5, binds to the host cell's outer membrane ferrichrome transporter, FhuA. The binding triggers structural changes in pb5 and eventually leads to DNA release from the phage capsid.