Part of a heterodimeric complex that catalyzes the two-step biosynthesis of 4-amino-4-deoxychorismate (ADC), a precursor of p-aminobenzoate (PABA) and tetrahydrofolate. In the first step, a glutamine amidotransferase (PabA) generates ammonia as a substrate that, along with chorismate, is used in the second step, catalyzed by aminodeoxychorismate synthase (PabB) to produce ADC. PabA converts glutamine into glutamate only in the presence of stoichiometric amounts of PabB. Also involved in the biosynthesis of anthranilate (By similarity). Complements a glutamine amidotransferase-negative mutant (PubMed:2123867). chorismate + L-glutamine = anthranilate + H(+) + L-glutamate + pyruvate chorismate + L-glutamine = 4-amino-4-deoxychorismate + L-glutamate Amino-acid biosynthesis; L-tryptophan biosynthesis; L-tryptophan from chorismate: step 1/5. Cofactor biosynthesis; tetrahydrofolate biosynthesis; 4-aminobenzoate from chorismate: step 1/2. Monomer. Heterodimer consisting of two non-identical subunits: a glutamine amidotransferase subunit (PabA) and a aminodeoxychorismate synthase subunit (PabB) (By similarity). Repressed by tryptophan. Requires tryptophan and has a partial requirement for p-aminobenzoic acid for growth.