Catalysis of the reaction: L-glutamine + chorismate = 4-amino-4-deoxychorismate + L-glutamate. It is composed of two enzymatic activities (which may be present on one or two polypeptides); the first is a glutaminase which yields ammonia from glutamine, releasing glutamate. The ammonia is used by the second activity which catalyzes the amination of chorismate to form 4-amino-4-deoxychorismate.
Source:EC:2.6.1.85,
RHEA:11672
Comment
Note that the name 'para-aminobenzoic acid synthase' was initially given to the 'aminodeoxychorismate synthase' activity before the additional 4-amino-4-deoxychorismate lyase activity was discovered. It is the lyase activity that actually produces para-aminobenzoic acid from 4-amino-4-deoxychorismate.