Metal-binding remains crucial to life today, so the authors sought the structure of the original proteins by looking for common features in proteins that fulfill this role across the tree of life.
"We saw that the metal-binding cores of existing proteins are indeed similar even though the proteins themselves may not be," said study author Professor Yana Bromberg in a statement.Curiously, these blocks were also found in other regions of the proteins, not just metal-binding cores, and in many other proteins that were not considered in our study.