Pseudomonas putida Tryptophan Synthetase

The two protein components of Pseudomonas putida tryptophan synthetase have been purified to homogeneity. Although there is general similarity between the Pseudomonas enzyme and that of the enteric bacteria, many differences were found. Components from Escherichia coli and P. putida do not stimulate each other enzymatically, and the enzymes differ in their response to monovalent cations. Serine deamination occurs best with the intact enzyme of P. putida , not with the β 2 subunit alone as in E. coli . The amino acid compositions of the α subunits differ appreciably. These findings extend earlier studies showing differences between enteric organisms and pseudomonads in the regulation and genetic organization of the enzymes of the tryptophan pathway.