The enzyme, characterized from the bacterium Salmonella enterica, can phosphorylate exogeneously-provided 5-amino-1-(beta-D-ribosyl)imidazole to form 5-amino-1-(5-phospho-beta-D-ribosyl)imidazole (AIR), an important intermediate in the production of both purine mononucleotides and the hydroxymethyl pyrimidine moiety of thiamine.
The stm4066 gene product of Salmonella enterica serovar Typhimurium has aminoimidazole riboside (AIRs) kinase activity and allows AIRs to satisfy the thiamine requirement of pur mutant strains.