| Abstract: | Mutant strains of Escherichia coli K-12 were isolated possessing mutations which affected the tyrosine-inhibitable 3-deoxy-d-arabinoheptulosonic acid-7-phosphate (DAHP) synthetase, the phenylalanine-inhibitable DAHP synthetase, or the tryptophan-repressible DAHP synthetase. The mutations causing the loss of each of these activities have been mapped and are widely separated from each other on the E. coli chromosome. Chromatography on diethylaminoethyl cellulose columns allowed the recognition of four peaks of activity. |
