The invention relates to a lyase and a lyase-encoding DNA, to vectors containing the DNA and to a method for the asymmetric synthesis of (S)-phenylacetylcarbinol. According to the invention, a lyase is provided, in which tryptophan is replaced with an amino acid at position 543 in protein ApPDC-E469G, said protein being modified with respect to the wild type of Aceobacter pasteurianus, or in which it is less space-filling than tryptophan. According to the invention, deoxyribonucleic acids are furthermore provided, which encode the lyase. (S)-phenylacetylcarbinol can be produced with the lyase according to the invention from the educts benzaldehyde and pyruvate or acetaldehyde with an enantiomeric excess of at least 94%.