Based on genetic blueprints, individual amino acids are assembled into long amino acid chains, the proteins, in the protein factories of our cells, the ribosomes. Each newly formed protein starts with the amino acid methionine. This amino acid is often split off again during protein synthesis, as soon as the growing amino acid chain leaves the protein factory through the “ribosomal tunnel.” In these cases, the excision of methionine is essential to ensure the subsequent function of the corresponding proteins in the cell.
The enzymes causing this cleavage are already known. According to their function, they are called methionine aminopeptidases (METAPs). Up to now, it was unclear how METAPs come into contact with the protein factories and, just at the right place and moment, cause the excision of methionine from specific proteins. Biologists Elke Deuerling, Martin Gamerdinger and…