Enzymes
| UniProtKB help_outline | 33,352 proteins |
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- Name help_outline 5-phospho-α-D-ribose 1-diphosphate Identifier CHEBI:58017 Charge -5 Formula C5H8O14P3 InChIKeyhelp_outline PQGCEDQWHSBAJP-TXICZTDVSA-I SMILEShelp_outline O[C@H]1[C@@H](O)[C@H](O[C@@H]1COP([O-])([O-])=O)OP([O-])(=O)OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 21 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ATP Identifier CHEBI:30616 (Beilstein: 3581767) help_outline Charge -4 Formula C10H12N5O13P3 InChIKeyhelp_outline ZKHQWZAMYRWXGA-KQYNXXCUSA-J SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,280 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,204 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline nicotinate Identifier CHEBI:32544 (Beilstein: 3539722) help_outline Charge -1 Formula C6H4NO2 InChIKeyhelp_outline PVNIIMVLHYAWGP-UHFFFAOYSA-M SMILEShelp_outline [O-]C(=O)c1cccnc1 2D coordinates Mol file for the small molecule Search links Involved in 16 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ADP Identifier CHEBI:456216 (Beilstein: 3783669) help_outline Charge -3 Formula C10H12N5O10P2 InChIKeyhelp_outline XTWYTFMLZFPYCI-KQYNXXCUSA-K SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 841 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline diphosphate Identifier CHEBI:33019 (Beilstein: 185088) help_outline Charge -3 Formula HO7P2 InChIKeyhelp_outline XPPKVPWEQAFLFU-UHFFFAOYSA-K SMILEShelp_outline OP([O-])(=O)OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1,129 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline nicotinate β-D-ribonucleotide Identifier CHEBI:57502 Charge -2 Formula C11H12NO9P InChIKeyhelp_outline JOUIQRNQJGXQDC-ZYUZMQFOSA-L SMILEShelp_outline O[C@H]1[C@@H](O)[C@@H](O[C@@H]1COP([O-])([O-])=O)[n+]1cccc(c1)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 8 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 992 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:36163 | RHEA:36164 | RHEA:36165 | RHEA:36166 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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A new paradigm for biochemical energy coupling. Salmonella typhimurium nicotinate phosphoribosyltransferase.
Vinitsky A., Grubmeyer C.
The pncB gene of Salmonella typhimurium was used to develop an overexpression system for nicotinate phosphoribosyltransferase (NAPRTase, EC 2.4.2.11), which forms nicotinate mononucleotide (NAMN) and PPi from nicotinate and alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP). NAPRTase hydrolyzes ATP i ... >> More
The pncB gene of Salmonella typhimurium was used to develop an overexpression system for nicotinate phosphoribosyltransferase (NAPRTase, EC 2.4.2.11), which forms nicotinate mononucleotide (NAMN) and PPi from nicotinate and alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP). NAPRTase hydrolyzes ATP in 1:1 molar stoichiometry to NAMN synthesis. Hydrolysis of ATP alters the ratio of products/substrates for the reaction nicotinate + PRPP <--> NAMN + PPi from its equilibrium value of 0.67 to a steady-state value of 1100. The energy for the maintenance of this ratio must come from ATP hydrolysis. However, in contrast to other ATP-utilizing enzymes, when all ATP is hydrolyzed the unfavorable product/substrate ratio collapses. ATP/ADP exchange results suggest that the overall reaction involves a phosphoenzyme (E-P) arising from E.ATP. Km values for nicotinate and PRPP each decreased by 200-fold when ATP was present to phosphorylate the enzyme. PPi stimulated the ATPase activity of the enzyme to Vmax values, suggesting that PPi formation during catalysis provides a trigger for cleavage of the putative E-P in the overall reaction and regenerates the low affinity form of the enzyme. A model is presented in which alternation of high and low affinity forms of NAPRTase provides a "steady-state" coupling between ATP hydrolysis and NAMN formation. << Less