Escherichia virus T4 is a species of bacteriophages that infect Escherichia coli bacteria. It is a double-stranded DNA virus in the subfamily Tevenvirinae from the family Myoviridae. T4 is capable of undergoing only a lytic life cycle and not the lysogenic life cycle. The species was formerly named T-even bacteriophage, a name which also encompasses, among other strains, Enterobacteria phage T2, Enterobacteria phage T4 and Enterobacteria phage T6.
Escherichia virus T4
Survival curves for virus T4 with DNA damaged by UV (top) or MMC (bottom) after single virus T4 infecting host cells (monocomplexes) or two or more virus T4 simultaneously infecting host cells (multicomplexes).
Bacteriophage T4 structure as per construction from individual PDBs and cryoEMs
A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν, meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm.
Bacteriophage T2, a member of the Myoviridae due to its contractile tail
Félix d'Herelle conducted the first clinical application of a bacteriophage
George Eliava pioneered the use of phages in treating bacterial infections
In this electron micrograph of bacteriophages attached to a bacterial cell, the viruses are the size and shape of coliphage T1