SANTA CRUZ, Calif., March 19 (UPI) -- U.S. scientists have determined the three-dimensional structure of an RNA enzyme, or "ribozyme," involved in the creation of RNA molecules.
The work by University of California-Santa Cruz researchers provides insight into what might have been the first self-replicating molecule to arise billions of years ago on the evolutionary path toward the emergence of life.
"Which came first, nucleic acids or proteins? This question once seemed an intractable paradox, but with the discovery of ribozymes, it is now possible to imagine a prebiotic 'RNA World' in which self-replicating ribozymes accomplished both tasks," said William Scott, associate professor of chemistry and biochemistry.
Scott and postdoctoral researcher Michael Robertson determined the structure of a ribozyme joining two RNA subunits in the same reaction that's carried out in biological systems by the protein known as RNA polymerase.
The research appears in the March 16 issue of the journal Science.