| COG0005 | Purine nucleoside phosphorylase |
| COG0015 | Adenylosuccinate lyase |
| COG0026 | Phosphoribosylaminoimidazole carboxylase (NCAIR synthetase) |
| COG0027 | Formate-dependent phosphoribosylglycinamide formyltransferase (GAR transformylase) |
| COG0034 | Glutamine phosphoribosylpyrophosphate amidotransferase |
| COG0035 | Uracil phosphoribosyltransferase |
| COG0041 | Phosphoribosylcarboxyaminoimidazole (NCAIR) mutase |
| COG0044 | Dihydroorotase and related cyclic amidohydrolases |
| COG0046 | Phosphoribosylformylglycinamidine (FGAM) synthase, synthetase domain |
| COG0047 | Phosphoribosylformylglycinamidine (FGAM) synthase, glutamine amidotransferase domain |
| COG0104 | Adenylosuccinate synthase |
| COG0105 | Nucleoside diphosphate kinase |
| COG0125 | Thymidylate kinase |
| COG0127 | Xanthosine triphosphate pyrophosphatase |
| COG0138 | AICAR transformylase/IMP cyclohydrolase PurH (only IMP cyclohydrolase domain in Aful) |
| COG0150 | Phosphoribosylaminoimidazole (AIR) synthetase |
| COG0151 | Phosphoribosylamine-glycine ligase |
| COG0152 | Phosphoribosylaminoimidazolesuccinocarboxamide (SAICAR) synthase |
| COG0167 | Dihydroorotate dehydrogenase |
| COG0194 | Guanylate kinase |
| COG0207 | Thymidylate synthase |
| COG0208 | Ribonucleotide reductase, beta subunit |
| COG0209 | Ribonucleotide reductase, alpha subunit |
| COG0213 | Thymidine phosphorylase |
| COG0232 | dGTP triphosphohydrolase |
| COG0248 | Exopolyphosphatase |
| COG0274 | Deoxyribose-phosphate aldolase |
| COG0283 | Cytidylate kinase |
| COG0284 | Orotidine-5'-phosphate decarboxylase |
| COG0295 | Cytidine deaminase |
| COG0299 | Folate-dependent phosphoribosylglycinamide formyltransferase PurN |
| COG0402 | Cytosine deaminase and related metal-dependent hydrolases |
| COG0418 | Dihydroorotase |
| COG0458 | Carbamoylphosphate synthase large subunit (split gene in MJ) |
| COG0461 | Orotate phosphoribosyltransferase |
| COG0462 | Phosphoribosylpyrophosphate synthetase |
| COG0503 | Adenine/guanine phosphoribosyltransferases and related PRPP-binding proteins |
| COG0504 | CTP synthase (UTP-ammonia lyase) |
| COG0505 | Carbamoylphosphate synthase small subunit |
| COG0516 | IMP dehydrogenase/GMP reductase |
| COG0518 | GMP synthase - Glutamine amidotransferase domain |
| COG0519 | GMP synthase, PP-ATPase domain/subunit |
| COG0528 | Uridylate kinase |
| COG0537 | Diadenosine tetraphosphate (Ap4A) hydrolase and other HIT family hydrolases |
| COG0540 | Aspartate carbamoyltransferase, catalytic chain |
| COG0563 | Adenylate kinase and related kinases |
| COG0572 | Uridine kinase |
| COG0590 | Cytosine/adenosine deaminases |
| COG0634 | Hypoxanthine-guanine phosphoribosyltransferase |
| COG0717 | Deoxycytidine deaminase |
| COG0737 | 5'-nucleotidase/2',3'-cyclic phosphodiesterase and related esterases |
| COG0756 | dUTPase |
| COG0775 | Nucleoside phosphorylase |
| COG0788 | Formyltetrahydrofolate hydrolase |
| COG0813 | Purine-nucleoside phosphorylase |
| COG0856 | Orotate phosphoribosyltransferase homologs |
| COG1001 | Adenine deaminase |
| COG1051 | ADP-ribose pyrophosphatase |
| COG1102 | Cytidylate kinase |
| COG1328 | Oxygen-sensitive ribonucleoside-triphosphate reductase |
| COG1351 | Predicted alternative thymidylate synthase |
| COG1428 | Deoxynucleoside kinases |
| COG1435 | Thymidine kinase |
| COG1437 | Adenylate cyclase, class 2 (thermophilic) |
| COG1457 | Purine-cytosine permease and related proteins |
| COG1618 | Predicted nucleotide kinase |
| COG1780 | Protein involved in ribonucleotide reduction |
| COG1781 | Aspartate carbamoyltransferase, regulatory subunit |
| COG1816 | Adenosine deaminase |
| COG1828 | Phosphoribosylformylglycinamidine (FGAM) synthase, PurS component |
| COG1864 | DNA/RNA endonuclease G, NUC1 |
| COG1936 | Predicted nucleotide kinase (related to CMP and AMP kinases) |
| COG1953 | Cytosine/uracil/thiamine/allantoin permeases |
| COG1957 | Inosine-uridine nucleoside N-ribohydrolase |
| COG1972 | Nucleoside permease |
| COG2019 | Archaeal adenylate kinase |
| COG2065 | Pyrimidine operon attenuation protein/uracil phosphoribosyltransferase |
| COG2131 | Deoxycytidylate deaminase |
| COG2169 | Adenosine deaminase |
| COG2233 | Xanthine/uracil permeases |
| COG2759 | Formyltetrahydrofolate synthetase |
| COG2820 | Uridine phosphorylase |
| COG3072 | Adenylate cyclase |
| COG3194 | Ureidoglycolate hydrolase |
| COG3363 | Archaeal IMP cyclohydrolase |
| COG3613 | Nucleoside 2-deoxyribosyltransferase |
| COG4088 | Predicted nucleotide kinase |
| COG4266 | Allantoicase |
| COG4290 | Guanyl-specific ribonuclease Sa |
| COG4360 | ATP adenylyltransferase (5',5'''-P-1,P-4-tetraphosphate phosphorylase II) |
| COG4445 | Hydroxylase for synthesis of 2-methylthio-cis-ribozeatin in tRNA |
| COG4630 | Xanthine dehydrogenase, iron-sulfur cluster and FAD-binding subunit A |
| COG4631 | Xanthine dehydrogenase, molybdopterin-binding subunit B |
| COG4741 | Predicted secreted endonuclease distantly related to archaeal Holliday junction resolvase |
| COG5042 | Purine nucleoside permease |
