A Phospholipase with a Novel Catalytic Triad

Catalytic triads are a long-standing paradigm of enzyme catalysis. By using a "matched mutation" approach, that is, a simultaneous exchange of the protein (through mutagenesis) and the substrate (through substitution of oxygen atoms by sulfur atoms) followed by enzyme kinetic analysis, a novel catalytic triad (see figure) with an unusual amino acid composition is now proposed for a phospholipase that fulfills a dual function in catalysis.