A novel enzyme, L-lysine : pyruvate aminotransferase, catalyses the first step of lysine catabolism in Pichia guilliermondii

Abstract

A novel aminotransferase catalysing the first step of lysine catabolism, the oxidative transamination of the ε{lunate}-group of L-lysine, was found and characterised in the yeast Pichia guilliermondii. The enzyme, L-lysine : pyruvate aminotransferase (Lys-AT), is strongly derepressed in cells grown on L-lysine as sole nitrogen source and its activity is highly specific for both L-lysine and pyruvate. We could successfully isolate a regulatory mutant which is unable to use lysine as sole nitrogen source based on its inability to derepress the Lys-AT. © 1988.