Editorial : Professor Dr. Muhammad Mukhtar

Like humans, bacteria have their battles with viruses. Surprisingly, some bacteria have developed a unique defense mechanism, as revealed by two new studies published in Science. These bacteria create a brand-new gene, something they don't typically have, to stay safe from viral attacks. This gene, named neo by the researchers, produces a protein that effectively blocks the invading viruses.

This discovery challenges the traditional view of genetic information flow and opens up a world of possibilities. It suggests that similar hidden genes might exist in other organisms, including humans, and could revolutionize our understanding of genetic processes. The bacteria employ reverse transcriptase enzyme to create this new gene, which typically converts RNA into DNA. This enzyme, known for its role in viruses like HIV, is now used by bacteria to outsmart the viruses that infect them, known as phages.

The research teams behind this discovery deserve immense credit. They were inspired by an earlier mystery- a strange bacterial defense system scientists stumbled upon a few years ago but couldn't decipher. The new studies have now cracked the code. When under attack, bacteria use reverse transcriptase to generate the neo gene made from a small RNA segment. Interestingly, the gene is built with multiple copies of the same DNA sequence, a phenomenon that initially puzzled scientists.

This repetitive structure is critical to how the gene works. The bacteria cleverly link these repeated sequences to form a functioning gene promoter, a vital protein production component. The neo gene springs into action when the bacteria are under viral attack, forcing the bacterial cells into dormancy. This prevents the viruses from replicating and spreading.

Scientists still have to find out why bacteria use such a complicated method instead of constantly producing the antiviral protein. It might be because the protein is so powerful that it could harm the bacteria if continuously made. It could also be a way to outsmart the phages that usually destroy the bacterial DNA during infection.

Additional Readings:

1. Bacteria use ‘crazy molecular mechanism’ to fight viruses

2. De novo gene synthesis by an antiviral reverse transcriptase
3. Diverse enzymatic activities mediate antiviral immunity in prokaryotes