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UniProt functional annotation for P9WKE1 | ||
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| UniProt code: P9WKE1. |
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| Organism: | |
Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv). |
| Taxonomy: | |
Bacteria; Actinobacteria; Corynebacteriales; Mycobacteriaceae; Mycobacterium; Mycobacterium tuberculosis complex. |
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| Function: | |
Catalyzes the reversible phosphorylation of deoxythymidine monophosphate (dTMP) to deoxythymidine diphosphate (dTDP), using ATP as its preferred phosphoryl donor. Situated at the junction of both de novo and salvage pathways of deoxythymidine triphosphate (dTTP) synthesis, is essential for DNA synthesis and cellular growth. Has a broad specificity for nucleoside triphosphates, being highly active with ATP or dATP as phosphate donors, and less active with ITP, GTP, CTP and UTP. |
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| Catalytic activity: | |
Reaction=ATP + dTMP = ADP + dTDP; Xref=Rhea:RHEA:13517, ChEBI:CHEBI:30616, ChEBI:CHEBI:58369, ChEBI:CHEBI:63528, ChEBI:CHEBI:456216; EC=2.7.4.9; |
| Cofactor: | |
Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Note=Binds 1 Mg(2+) ion per subunit. This ion is required for catalysis, binding to the active site transiently (at the TMP-binding site), and probably acting as a clamp between the phosphoryl donor and acceptor.; |
| Activity regulation: | |
Competitively inhibited at the phosphate acceptor site by 3'-azido-3'-deoxythymidine monophosphate (AZT-MP) (in contrast to other TMPKs such as E.coli, in which it is a good substrate). Inhibition seems to result from the impossibility of magnesium binding. |
| Biophysicochemical properties: | |
Kinetic parameters: KM=0.1 mM for ATP (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; KM=4.5 uM for dTMP (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; KM=0.14 mM for dehydro-TMP (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; KM=2.10 mM for dUMP (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; Vmax=13 umol/min/mg enzyme with ATP and dTMP as substrates (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; Vmax=0.16 umol/min/mg enzyme with ATP and dehydro-TMP as substrates (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; Vmax=3.50 umol/min/mg enzyme with ATP and dUMP as substrates (at pH 7.4 and 30 degrees Celsius) {ECO:0000269|PubMed:11369858}; pH dependence: Optimum pH is 7.5-8.5. Inactive below pH 4.6. {ECO:0000269|PubMed:11369858, ECO:0000269|PubMed:12662932}; Temperature dependence: Highly thermostable. Is half-inactivated at 65 degrees Celsius. {ECO:0000269|PubMed:11369858}; |
| Pathway: | |
Pyrimidine metabolism; dTTP biosynthesis. |
| Subunit: | |
Homodimer. {ECO:0000269|PubMed:11369858}. |
| Domain: | |
The LID domain is a solvent-exposed domain that closes over the site of phosphoryl transfer upon ATP binding. |
| Mass spectrometry: | |
Mass=22635.89; Mass_error=2.23; Method=Electrospray; Evidence={ECO:0000269|PubMed:11369858}; |
| Miscellaneous: | |
Was identified as a high-confidence drug target. |
| Similarity: | |
Belongs to the thymidylate kinase family. {ECO:0000305}. |
Annotations taken from UniProtKB at the EBI.