Catalyzes the second and fifth step in the 'de novo' purine biosynthesis pathway; contains phosphoribosylamine--glycine ligase (GARS) and phosphoribosylformylglycinamidine cyclo-ligase (AIRS) activities. 2-formamido-N(1)-(5-O-phospho-beta-D-ribosyl)acetamidine + ATP = 5-amino-1-(5-phospho-beta-D-ribosyl)imidazole + ADP + H(+) + phosphate 5-phospho-beta-D-ribosylamine + ATP + glycine = ADP + H(+) + N(1)-(5-phospho-beta-D-ribosyl)glycinamide + phosphate Binds two magnesium or manganese ions per subunit. kcat is 27.3 sec(-1) for phosphoribosylamine--glycine ligase activity (at 37 degrees Celsius). Purine metabolism; IMP biosynthesis via de novo pathway; 5-amino-1-(5-phospho-D-ribosyl)imidazole from N(2)-formyl-N(1)-(5-phospho-D-ribosyl)glycinamide: step 2/2. Purine metabolism; IMP biosynthesis via de novo pathway; N(1)-(5-phospho-D-ribosyl)glycinamide from 5-phospho-alpha-D-ribose 1-diphosphate: step 2/2. Homodimer. Growth auxotrophic for adenine (PubMed:34416230). Avirulent in a mouse inhalation infection model (PubMed:34416230). Does not appear to affect production of the virulence factors melanin, protease, urease, or phospholipase B, or on capsule formation (PubMed:34416230). In the N-terminal section; belongs to the GARS family. In the C-terminal section; belongs to the AIR synthase family.