A simplified ancient enzyme, built from fewer building blocks, unexpectedly learned to make life's fuel

Proteins are built from amino acids, and early life may have had far fewer kinds to work with. Researchers at Waseda University and the RIKEN Center in Japan rebuilt an ancestral enzyme using a deliberately restricted set of amino acids — and one variant, missing the part textbooks say is essential, still folded correctly and did something unexpected: it converted two molecules of ADP into ATP, the fuel every cell runs on, plus AMP. The work, published in Angewandte Chemie International Edition, hints that the chemistry of life may have had more than one route to making energy — a clue to how metabolism began, written in a protein rebuilt to be simpler than nature's.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation