Rare ‘ambidextrous’ protein breaks rules of handedness

Scientists have discovered an ancient protein that has the rare property of being ‘ambidextrous’ — it can function in mirror-image forms. The protein contains a structure that’s symmetrical around an axis, which allows both ‘left-handed’ and ‘right-handed’ versions to bind to normal and mirror-image DNA. Why the structure is ambidextrous is unclear, but “a crazy explanation” is that it could have evolved when ‘mirror life’ — containing left-handed nucleic acids and right-handed proteins — existed on Earth.