Tagatose-6-phosphate kinase
In enzymology, a tagatose-6-phosphate kinase (EC 2.7.1.144) is an enzyme that catalyzes the chemical reaction
- ATP + D-tagatose 6-phosphate ADP + D-tagatose 1,6-bisphosphate
| tagatose-6-phosphate kinase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC number | 2.7.1.144 | ||||||||
| CAS number | 39434-00-9 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
Thus, the two substrates of this enzyme are ATP and D-tagatose 6-phosphate, whereas its two products are ADP and D-tagatose 1,6-bisphosphate.
This enzyme belongs to the phosphofructokinase B (PfkB) or Ribokinase family of sugar kinases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor.[1][2] The systematic name of this enzyme class is ATP:D-tagatose-6-phosphate 1-phosphotransferase. The members of the PfkB/RK family are identified by the presence of three conserved sequence motifs and their enzymatic activity generally shows a dependence on the presence of pentavalent ions.[1][2][3] This enzyme participates in galactose metabolism.
Structural studies
As of late 2007, five structures have been solved for this class of enzymes, with PDB accession codes 2AWD, 2F02, 2JG1, 2JGV, and 2Q5R.
References
- Park J, Gupta RS: Adenosine kinase and ribokinase--the RK family of proteins. Cell Mol Life Sci 2008, 65: 2875-2896.
- Bork P, Sander C, Valencia A: Convergent evolution of similar enzymatic function on different protein folds: the hexokinase, ribokinase, and galactokinase families of sugar kinases. Protein Sci 1993, 2: 31-40.
- Maj MC, Singh B, Gupta RS: Pentavalent ions dependency is a conserved property of adenosine kinase from diverse sources: identification of a novel motif implicated in phosphate and magnesium ion binding and substrate inhibition. Biochemistry 2002, 41: 4059-4069.
- Nobelmann B, Lengeler JW (1995). "Sequence of the gat operon for galactitol utilization from a wild-type strain EC3132 of Escherichia coli". Biochim. Biophys. Acta. 1262 (1): 69–72. doi:10.1016/0167-4781(95)00053-j. PMID 7772602.