Occurrence of a Novel Lyase Catalyzing β-Elimination Reaction toward threo-3-Chloro-L-aspartate in Pseudomonas putida TPU 7151

Abstract

A bacterium, Pseudomonas putida TPU 7151, which degrades threo-3-chloro-L-aspartate, was isolated from soil and the enzyme responsible for the degradation of the amino acid was partially purified from the cell-free extract of the strain. The enzyme, which required PLP for its reaction, catalyzed a stoichiometric β-elimination reaction of threo-3-chloro-L-aspartate to form oxaloacetate, Cl^-, and NH₄⁺. The enzyme was active toward only threo-3-chloro-L-aspartate and L-cysteine, but did not catalyze a β-replacement reaction. The enzyme can be classified in a new group of PLP-dependent amino acid-lyases [EC 4.2.1.-].