The enzyme is composed of two parts, PabA and PabB. In the absence of PabA and glutamine, PabB converts ammonia and chorismate into 4-amino-4-deoxychorismate (in the presence of Mg2+). PabA converts glutamine into glutamate only in the presence of stoichiometric amounts of PabB. This enzyme is coupled with EC 188.8.131.52, aminodeoxychorismate lyase, to form 4-aminobenzoate.
EC 184.108.40.206 created 2003 as EC 220.127.116.11, transferred 2007 to EC 18.104.22.168