A groundbreaking study conducted by a team from the Earth-Life Science Institute in Tokyo, along with collaborators from the Hebrew University of Jerusalem and the Weizmann Institute of Science, has revealed that an ancient protein can function even when its molecular structure is mirrored.

Surprisingly, the research showed that the mirror-image HhH motif successfully binds to double-stranded DNA, defying expectations that its reversed handedness would hinder its functionality.

This discovery raises further questions about the evolutionary reasons behind the protein's ambidexterity, possibly linked to ancient forms of life.

The study's results challenge long-held beliefs about molecular design, suggesting that this nucleic acid-binding protein can operate in a 'mirror world'.

This ancient protein, known as the helix-hairpin-helix (HhH) motif, demonstrates a phenomenon termed 'functional ambidexterity,' as it can bind to both standard and mirror-image versions of DNA and RNA.

Initially considered a 'crazy' hypothesis, the study validated its claims through laboratory experiments and molecular simulations, which demonstrated similar binding characteristics between the natural and mirror-image proteins.

The binding kinetics and mutation effects revealed surprising similarities between the natural and mirror-image proteins, indicating a potential link in their binding modes at the molecular level.

Researchers speculate that the ability of the HhH motif to function in both handed forms may reflect ancient biological processes, possibly hinting at the existence of mirror-image life forms in the distant past.

The research was led by a collaborative team including Prof. Liam M. Longo and Prof. Norman Metanis, and was published in the journal Angewandte Chemie.

Typically, life on Earth exhibits homochirality, where proteins are composed of left-handed amino acids and nucleic acids consist of right-handed sugars, making this finding particularly unexpected.

This study marks the first known instance of ambidextrous proteins binding to nucleic acids, prompting further exploration into the evolutionary implications of this phenomenon.

The findings open new avenues for research into other proteins that may exhibit similar ambidextrous properties, challenging previous beliefs about molecular design.