Catalyzes the formation of phosphoribosylamine from phosphoribosylpyrophosphate (PRPP) and glutamine. 5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate = 5-phospho-alpha-D-ribose 1-diphosphate + H2O + L-glutamine Binds 1 Mg(2+) ion per subunit. Binds 1 [4Fe-4S] cluster per subunit. Activated by the substrate 5-phospho-alpha-D-ribosyl-1-pyrophosphate and inhibited by the purine ribonucleotides, the end products of purine biosynthesis. Purine metabolism; IMP biosynthesis via de novo pathway; N(1)-(5-phospho-D-ribosyl)glycinamide from 5-phospho-alpha-D-ribose 1-diphosphate: step 1/2. Homotetramer. Expressed at a high level in brain, heart, liver and stomach. In the C-terminal section; belongs to the purine/pyrimidine phosphoribosyltransferase family.