FIG. 1.

Relevant metabolic pathways. (A) Illustrated are the biosynthetic pathways involved in purine and thiamine synthesis. Names of genes whose products are known are indicated. The reaction(s) involved in the formation of PRA independent of PurF has not been defined biochemically or genetically. (B) Glycolysis, the pentose phosphate pathway, and the Entner-Doudoroff pathway are schematically represented. Names of genes whose products are required are indicated. Abbreviations: P, phosphate; PRPP, 5-phosphoribosyl-1-pyrophosphate AIR, aminoimidazole ribotide; PP, pyrophosphate; THZ-P, 4-methyl-5-(β-hydroxyethyl)-thiazole phosphate; TMP, thiamine monophosphate; G-3-P, glyceraldehyde-3-phosphate; DHAP, dihydroxyacetone phosphate; PEP, phosphoenolpyruvate; TCA, tricarboxylic acid.