Reconstruction of purine biosynthetic pathway in C. thermocellum DSM1313. Dotted lines indicate multistep catalysis. Putative genes involved in each step are present in gene abbreviations with locus numbers. Carbons from C1 metabolism are labeled in red. ADSL, adenylosuccinate lyase; AIRC, 5-aminoimidizole ribonucleotide carboxylase; AIRS, 5-aminoimidizole ribonucleotide synthetase; ATIC, phosphoribosylaminoimidazolecarboxamide formyltransferase/IMP cyclohydrolase; GARS, glycinamide ribonucleotide synthetase; GARTFase, phosphoribosylglycinamide formyltransferase; IGPS, imidazole glycerol phosphate synthase; IMP, inosinate mononucleotide phosphate; PFAS, phosphoribosylformylglycinamidine synthase; PPAT, phosphoribosyl pyrophosphate amidotransferase; PRPS1, phosphoribosyl pyrophosphate synthetase 1.