Scientists Discover a Bizarre New Way Life Can Make DNA… Without DNA

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Researchers have identified an unconventional mechanism by which bacteria generate DNA, challenging conventional understanding of genetic information transfer. Scientists studying the bacterium Escherichia coli discovered that a protein-based immune system creates DNA through an unexpected pathway that does not rely on traditional nucleic acid templates.

In this newly identified system, called defense-associated reverse transcriptases (DRT), two separate enzymes work together to construct DNA strands through fundamentally different processes. One enzyme operates in the conventional manner, using RNA as a template to synthesize DNA. The second enzyme, however, employs an entirely novel approach: specific amino acids within the protein itself serve as the template, directing which DNA building blocks are incorporated into the emerging strand. This results in a simple repeating sequence rather than complex genetic instructions.

Researchers confirmed this mechanism through structural analysis and targeted experiments. By modifying the critical amino acids, scientists demonstrated their essential role in both DNA synthesis and the bacterium’s defense against viral attacks. The two independently produced strands subsequently pair together to form double-stranded DNA.

This discovery reveals an unusual biological information pathway where protein sequences directly determine DNA sequences—essentially reversing the typical flow of genetic data. The system appears to function as part of the bacterium’s immune arsenal, suggesting that nature has evolved diverse strategies for managing genetic material beyond the well-established models scientists have long studied.

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Originally reported by Sciencealert →