trPE

trpE is a bacterial gene that encodes one subunit of the enzyme anthranilate synthase, a key enzyme in the tryptophan biosynthesis pathway. In many bacteria, anthranilate synthase is a heteromer consisting of two distinct subunits; TrpE typically serves as the larger subunit (anthranilate synthase component I) and functions in concert with a partner subunit encoded by another gene to form the active enzyme that converts chorismate to anthranilate.

Function and mechanism: The TrpE-containing complex catalyzes the amination of chorismate to produce anthranilate, using ammonia supplied by the partner subunit from glutamine metabolism. This first committed step is essential for subsequent steps in tryptophan synthesis.

Genetic context and regulation: trpE is commonly part of the trp operon, a cluster of genes encoding enzymes of the tryptophan biosynthesis pathway. Expression is tightly regulated by tryptophan availability via the Trp repressor and attenuation mechanisms, so that production is increased when tryptophan is scarce and repressed when it is abundant.

Relation and applications: The TrpE subunit is broadly conserved in bacteria and archaea that synthesize tryptophan. It is a target of interest in antimicrobial research and a focal point in metabolic engineering aimed at increasing microbial tryptophan production.