Enzymes
| UniProtKB help_outline | 4 proteins |
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- Name help_outline adenosine Identifier CHEBI:16335 (CAS: 58-61-7) help_outline Charge 0 Formula C10H13N5O4 InChIKeyhelp_outline OIRDTQYFTABQOQ-KQYNXXCUSA-N SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O 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 GTP Identifier CHEBI:37565 (Beilstein: 5211792) help_outline Charge -4 Formula C10H12N5O14P3 InChIKeyhelp_outline XKMLYUALXHKNFT-UUOKFMHZSA-J SMILEShelp_outline Nc1nc2n(cnc2c(=O)[nH]1)[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 94 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline GDP Identifier CHEBI:58189 Charge -3 Formula C10H12N5O11P2 InChIKeyhelp_outline QGWNDRXFNXRZMB-UUOKFMHZSA-K SMILEShelp_outline Nc1nc2n(cnc2c(=O)[nH]1)[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 184 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline AMP Identifier CHEBI:456215 Charge -2 Formula C10H12N5O7P InChIKeyhelp_outline UDMBCSSLTHHNCD-KQYNXXCUSA-L SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 512 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,521 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:52532 | RHEA:52533 | RHEA:52534 | RHEA:52535 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Identification and characterization of a unique adenosine kinase from Mycobacterium tuberculosis.
Long M.C., Escuyer V., Parker W.B.
Adenosine kinase (AK) is a purine salvage enzyme that catalyzes the phosphorylation of adenosine to AMP. In Mycobacterium tuberculosis, AK can also catalyze the phosphorylation of the adenosine analog 2-methyladenosine (methyl-Ado), the first step in the metabolism of this compound to an active fo ... >> More
Adenosine kinase (AK) is a purine salvage enzyme that catalyzes the phosphorylation of adenosine to AMP. In Mycobacterium tuberculosis, AK can also catalyze the phosphorylation of the adenosine analog 2-methyladenosine (methyl-Ado), the first step in the metabolism of this compound to an active form. Purification of AK from M. tuberculosis yielded a 35-kDa protein that existed as a dimer in its native form. Adenosine (Ado) was preferred as a substrate at least 30-fold (Km = 0.8 +/-0.08 microM) over other natural nucleosides, and substrate inhibition was observed when Ado concentrations exceeded 5 micro M. M. tuberculosis and human AKs exhibited different affinities for methyl-Ado, with Km values of 79 and 960 microM, respectively, indicating that differences exist between the substrate binding sites of these enzymes. ATP was a good phosphate donor (Km = 1100 +/-140 microM); however, the activity levels observed with dGTP and GTP were 4.7 and 2.5 times the levels observed with ATP, respectively. M. tuberculosis AK activity was dependent on Mg2+, and activity was stimulated by potassium, as reflected by a decrease in the Km and an increase in Vmax for both Ado and methyl-Ado. The N-terminal amino acid sequence of the purified enzyme revealed complete identity with Rv2202c, a protein currently classified as a hypothetical sugar kinase. When an AK-deficient strain of M. tuberculosis (SRICK1) was transformed with this gene, it exhibited a 5,000-fold increase in AK activity compared to extracts from the original mutants. These results verified that the protein that we identified as AK was coded for by Rv2202c. AK is not commonly found in bacteria, and to the best of our knowledge, M. tuberculosis AK is the first bacterial AK to be characterized. The enzyme shows greater sequence homology with ribokinase and fructokinase than it does with other AKs. The multiple differences that exist between M. tuberculosis and human AKs may provide the molecular basis for the development of nucleoside analog compounds with selective activity against M. tuberculosis. << Less
J. Bacteriol. 185:6548-6555(2003) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.