TABLE 4.

Effect of aromatic amino acids on mutant AtCM1 and AtCM3

Reactions were performed as described under “Experimental Procedures.” Conversion of chorismate to prephenate was determined while varying each amino acid concentration. All parameters are expressed as an average ± S.E. for an n = 3.

	Ligand	EC50	Apoenzyme Vmax	Fully bound Vmax
		μm	μmol min−1 mg protein−1	μmol min−1 mg protein−1
AtCM1 mutant
G149D	Trp	7.9 ± 0.1	1.49 ± 0.32	20.0 ± 0.5
G149A	Trp	11.7 ± 0.2	1.76 ± 0.12	14.9 ± 0.2
AtCM3 mutant
D132G	Trp	1.4 ± 0.1	2.52 ± 0.42	9.65 ± 0.44
D132G	Phe	3.2 ± 0.1	2.85 ± 0.10	0.35 ± 0.06
D132G	Tyr	30.9 ± 2.0	2.63 ± 0.73	0.42 ± 0.10