https://phys.org/news/2019-01-biology-ancient-ancestor.html

What's more, the A*STAR investigators found that one of these archaeal proteins, profilin, that serves to bind and regulate the dynamics of a cytoskeletal protein called actin—had the same function as its counterpart in eukaryotes. The primordial profilin could even bind actin derived from a mammal.

"After around two billion years of divergent evolution, it is staggering that these proteins are compatible," says Robert Robinson, a research director at the A*STAR Institute of Molecular and Cell Biology, who led the study published in Nature.