The origin of life is a $64,000 question. Dr. John Chaput is particularly intrigued by the origin of replication and how the first genetic molecules were created. You may have learnt about DNA and RNA, but Dr. Chaput believes that it is TNA (threose nucleic acid) that was the first carrier of genetic information. In a recent Nature Chemistry article, his group described the Darwinian evolution of TNA sequences that could perform many of the basic tasks normally accomplished by RNA and DNA. Dr. Chaput showed that TNA could form Watson-Crick base pairs with DNA and that TNA double strands could be engineered to display highly specific binding to the protein thrombin. TNA is more likely candidate than DNA or RNA for the first genetic molecule because of its simplicity, containing a tetrose sugar backbone that could have been synthesized pre-biotically from two identical two-carbon precursors.
