Amazing stuff!
"Phages, viruses that attack bacteria, have a head and a tail. The head contains the phage’s genetic material and the tail is used to identify a potential host, that is, a bacterial cell into which it can inject this material. Once the injection is complete, the phage hijacks the bacterium’s cellular machinery and forces it to produce new copies of itself, which ultimately burst the cell and infect other bacteria in the colony. In a new study ... researchers reveal a bacterial immune system that thwarts the phages’ plot by attaching a small protein molecule to their tails. The components of this new immune system are similar in structure to a human immunity mechanism, and they might help reveal how this mechanism works and how our own immune system has evolved. ...
The first antiphage defense mechanisms in bacteria were discovered in the 1960s, but only a handful of such mechanisms were known until recently. The most famous of these is CRISPR-Cas9, whose discovery led to a revolution in gene editing. In recent years, however, there has been a wave of new findings in the field, leading to the discovery of more than 150 new bacterial immune systems with varied modes of action."
The first antiphage defense mechanisms in bacteria were discovered in the 1960s, but only a handful of such mechanisms were known until recently. The most famous of these is CRISPR-Cas9, whose discovery led to a revolution in gene editing. In recent years, however, there has been a wave of new findings in the field, leading to the discovery of more than 150 new bacterial immune systems with varied modes of action."
From the abstract:
"Several immune pathways in humans conjugate ubiquitin-like proteins to virus and host molecules as a means of antiviral defence. Here we studied an antiphage defence system in bacteria, comprising a ubiquitin-like protein, ubiquitin-conjugating enzymes E1 and E2, and a deubiquitinase. We show that during phage infection, this system specifically conjugates the ubiquitin-like protein to the phage central tail fibre, a protein at the tip of the tail that is essential for tail assembly as well as for recognition of the target host receptor. Following infection, cells encoding this defence system release a mixture of partially assembled, tailless phage particles and fully assembled phages in which the central tail fibre is obstructed by the covalently attached ubiquitin-like protein. These phages show severely impaired infectivity, explaining how the defence system protects the bacterial population from the spread of phage infection. Our findings demonstrate that conjugation of ubiquitin-like proteins is an antiviral strategy conserved across the tree of life."
Bacteria conjugate ubiquitin-like proteins to interfere with phage assembly (no public access)
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