We may have had several billion years under our belts to figure it out, but scientists today continue to be puzzled by how early cellular life on Earth first came to be. And, more precisely, the chemical compounds which allowed it to happen. Now it seems a new study might be able to provide some of the answers, after a team of chemists stumbled upon the ‘missing’ compound that could have been the catalyst for this epic journey to begin. Researchers have long speculated that a chemical reaction called phosphorylation was a crucial step in the arrival of early life forms. This is because in order for life to come into existence it needed a few simple ingredients - strands of nucleotides to store genetic information, chains of amino acids for cell function, and lipids to form cell walls and other structures. These are just basic requirements of all biological structures. Despite knowing this, scientists had never been able to find a phosphorylating chemical agent that would have plausibly been around at this time, in the right quantities, in the right place, to serve as the trigger. But now researchers at the Scripps Research Institute have found one that could have played this central role: diamidophosphate (DAP). Senior author Ramanarayanan Krishnamurthy and his colleagues have previously shown how DAP is able to generate a variety of simple sugars that are present in early life forms. “That in turn would have allowed other chemistries that were not possible before, potentially leading to the first simple, cell-based living entities,” said Krishnamurthy. “It reminds me of the fairy godmother in Cinderella, who waves a wand and poof, poof, poof, everything simple is transformed into something more complex and interesting,” he added. It might have been able to do what early life forms required, but is there evidence that this compound even existed in this period? Astronomers have found that this magical chemical compound would have indeed been around in the form of phosphorus-nitrogen compounds in the gas and dust of interstellar space. And it continues to exist in humans today. “DAP phosphorylates via the same phosphorus-nitrogen bond breakage and under the same conditions as protein kinases, which are ubiquitous in present-day life forms...it also closely resembles what is seen in the reactions at the heart of every cell’s metabolic cycle,” said Krishnamurthy.