Meet the T4 bacteriophage, or “eat bacteria”!
Bacteriophages are different than the previous in the series because these viruses only infect bacterial cells, not human cells.
T4 bacteriophages are non-enveloped, form a head-tail structure, and carry a linear double-stranded DNA (dsDNA) genome about 169kb in length.
These complex structures work together to bind to a target cell, contract their tail, and inject their genome. The capsid head is an elongated icosahedral (typically about 137nm in length) and it carries the genome. The bacteriophage uses it’s long fibers (usually about 160nm in length) to recognize and bind to cells and the tail is hollow so that it can pass it’s genome from the head into the cell after binding. These viruses work quickly, and have shown to form new particles inside a host cell within 12 minutes of binding!
Bacteriophages were first discovered in 1915 and 1917 by an English scientist (Twort) and a French scientist (d’Hérelle), respectively. They were not isolated and named until the 1930/40s. Since then, bacteriophages have been a model organism for studying microbiology and molecular biology.
Posted on Instagram on March 14, 2021.