Aminoacyl-tRNA synthetases, which help translate the genetic code into protein, also function in angiogenesis, fat metabolism, and more.
For as long as living things have been building proteins based on the code carried by messenger RNA molecules, aminoacyl-tRNA synthetases have been there. These enzymes, AARSs for short, link transfer RNAs (tRNAs) to the corresponding amino acids. That would seem to be a big enough job for one class of enzymes—and when protein-based life began, it was. But as organisms became more complex, AARSs picked up additional domains that allow them to do much more.
“By the time you get to humans, the synthetase has become highly decorated” with those additional domains, says Paul Schimmel, a Scripps Research Institute biochemist who studies these add-on jobs.