A recent discovery could one day see viruses used to combat bacteria.

An international team of researchers has uncovered a significant discovery in the ongoing battle against harmful bacteria. 

The research, which focuses on bacteriophages - viruses that infect bacteria - reveals new insights into how these viruses can be utilised as alternatives to antibiotics in human health and agriculture.

Bacteria, much like humans, have their own defence mechanisms to protect against viral invaders. 

To understand how phages counteract these bacterial defences, the research team, led by Professor Peter Fineran from the University of Otago in New Zealand, examined a particular protein used by phages. 

This protein was previously known to bind DNA; however, the team discovered that it also has a mechanism to bind RNA.

The study focused on a protein involved in the phages' deployment of anti-CRISPR, a method used to block the CRISPR-Cas immune system of bacteria.

Researchers say it is critical to understand bacterial defence mechanisms, such as CRISPR, which are analogous to the human immune system's response to viruses. This knowledge helps identify appropriate phages to use as antimicrobials. 

The research unveiled a new aspect of how phages deploy their anti-CRISPRs. 

The experts already knew a particular phage protein has a domain common in many proteins involved in gene regulation, and that this helix-turn-helix (HTH) domain was known to bind DNA sequences and regulate gene activity. 

However, the team discovered that this domain is more versatile than previously thought.

“What we found is the HTH domain of this protein is much more versatile and exhibits a regulatory mode which was previously unknown. It can use this domain to not only bind DNA, but also its RNA transcript, the molecule which acts as a mediator between the DNA sequence and the anti-CRISPR encoded in it,” said Professor Peter Fineran from the University of Otago.

The findings have significant implications for understanding gene regulation. 

“Unravelling this unexpectedly complex regulation is important progress when it comes to understanding how phages can evade CRISPR-Cas defences and kill target bacteria in a range of applications,” Professor Fineran said. 

This discovery is particularly exciting because it reveals a novel regulatory mechanism in a well-studied family of proteins. 

“This finding has the potential to change the way the field views the function and mechanism of this critical and widespread protein domain, and could have big implications for our understanding of gene regulation,” he added.

The full study is accessible here.