Detection of Covalent Intermediates Formed in the Reaction of 4-Amino-4-deoxychorismate Synthase

摘要

The enzyme 4-amino-4-deoxychorismate synthase (ADCS) catalyses the first committed step on the folate biosynthesis pathway in microorganisms and plants.ADCS converts chorismate (1),the product of the shikimate pathway,to 4-amino-4-deoxy-chorismate (ADC,2;Scheme 1).ADC lyase then catalyses the elimination of pyruvate from ADC to produce the folate precursor p-aminobenzoate (3).A mechanism for ADCS involving an enzyme-bound covalent intermediate 4 was recently proposed (Figure 1,panel I).In this communication we provide the first direct experimental evidence for this covalent intermediate.