Tagatose-6-phosphate kinase

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tagatose-6-phosphate kinase
Identifiers
EC no. 2.7.1.144
CAS no. 39434-00-9
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BRENDA BRENDA entry
ExPASy NiceZyme view
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MetaCyc metabolic pathway
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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

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. 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. 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.</ref> 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.

Related Research Articles

<span class="mw-page-title-main">Glycolysis</span> Catabolic pathway

Glycolysis is the metabolic pathway that converts glucose into pyruvate, and in most organisms, occurs in the liquid part of cells, the cytosol. The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH). Glycolysis is a sequence of ten reactions catalyzed by enzymes.

<span class="mw-page-title-main">Phosphofructokinase 1</span> Class of enzymes

Phosphofructokinase-1 (PFK-1) is one of the most important regulatory enzymes of glycolysis. It is an allosteric enzyme made of 4 subunits and controlled by many activators and inhibitors. PFK-1 catalyzes the important "committed" step of glycolysis, the conversion of fructose 6-phosphate and ATP to fructose 1,6-bisphosphate and ADP. Glycolysis is the foundation for respiration, both anaerobic and aerobic. Because phosphofructokinase (PFK) catalyzes the ATP-dependent phosphorylation to convert fructose-6-phosphate into fructose 1,6-bisphosphate and ADP, it is one of the key regulatory steps of glycolysis. PFK is able to regulate glycolysis through allosteric inhibition, and in this way, the cell can increase or decrease the rate of glycolysis in response to the cell's energy requirements. For example, a high ratio of ATP to ADP will inhibit PFK and glycolysis. The key difference between the regulation of PFK in eukaryotes and prokaryotes is that in eukaryotes PFK is activated by fructose 2,6-bisphosphate. The purpose of fructose 2,6-bisphosphate is to supersede ATP inhibition, thus allowing eukaryotes to have greater sensitivity to regulation by hormones like glucagon and insulin.

<span class="mw-page-title-main">PFP (enzyme)</span>

Diphosphate—fructose-6-phosphate 1-phosphotransferase also known as PFP is an enzyme of carbohydrate metabolism in plants and some bacteria. The enzyme catalyses the reversible interconversion of fructose 6-phosphate and fructose 1,6-bisphosphate using inorganic pyrophosphate as the phosphoryl donor:

<span class="mw-page-title-main">Phosphofructokinase 2</span> Class of enzymes

Phosphofructokinase-2 (6-phosphofructo-2-kinase, PFK-2) or fructose bisphosphatase-2 (FBPase-2), is an enzyme indirectly responsible for regulating the rates of glycolysis and gluconeogenesis in cells. It catalyzes formation and degradation of a significant allosteric regulator, fructose-2,6-bisphosphate (Fru-2,6-P2) from substrate fructose-6-phosphate. Fru-2,6-P2 contributes to the rate-determining step of glycolysis as it activates enzyme phosphofructokinase 1 in the glycolysis pathway, and inhibits fructose-1,6-bisphosphatase 1 in gluconeogenesis. Since Fru-2,6-P2 differentially regulates glycolysis and gluconeogenesis, it can act as a key signal to switch between the opposing pathways. Because PFK-2 produces Fru-2,6-P2 in response to hormonal signaling, metabolism can be more sensitively and efficiently controlled to align with the organism's glycolytic needs. This enzyme participates in fructose and mannose metabolism. The enzyme is important in the regulation of hepatic carbohydrate metabolism and is found in greatest quantities in the liver, kidney and heart. In mammals, several genes often encode different isoforms, each of which differs in its tissue distribution and enzymatic activity. The family described here bears a resemblance to the ATP-driven phospho-fructokinases, however, they share little sequence similarity, although a few residues seem key to their interaction with fructose 6-phosphate.

<span class="mw-page-title-main">Phosphofructokinase</span> Enzyme in glycolysis

Phosphofructokinase (PFK) is a kinase enzyme that phosphorylates fructose 6-phosphate in glycolysis.

<span class="mw-page-title-main">Fructose-bisphosphate aldolase</span>

Fructose-bisphosphate aldolase, often just aldolase, is an enzyme catalyzing a reversible reaction that splits the aldol, fructose 1,6-bisphosphate, into the triose phosphates dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (G3P). Aldolase can also produce DHAP from other (3S,4R)-ketose 1-phosphates such as fructose 1-phosphate and sedoheptulose 1,7-bisphosphate. Gluconeogenesis and the Calvin cycle, which are anabolic pathways, use the reverse reaction. Glycolysis, a catabolic pathway, uses the forward reaction. Aldolase is divided into two classes by mechanism.

Glucose-1,6-bisphosphate synthase is a type of enzyme called a phosphotransferase and is involved in mammalian starch and sucrose metabolism. It catalyzes the transfer of a phosphate group from 1,3-bisphosphoglycerate to glucose-1-phosphate, yielding 3-phosphoglycerate and glucose-1,6-bisphosphate.

In enzymology, 1-phosphatidylinositol-4-phosphate 5-kinase is an enzyme that catalyzes the chemical reaction

In enzymology, a 1-phosphatidylinositol-5-phosphate 4-kinase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">1-phosphofructokinase</span> InterPro Family

In enzymology, 1-phosphofructokinase is an enzyme that catalyzes the chemical reaction

In enzymology, an ADP-specific phosphofructokinase is an enzyme that catalyzes the chemical reaction

In enzymology, a dihydrostreptomycin-6-phosphate 3'alpha-kinase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Inosine kinase</span>

In enzymology, an inosine kinase is an enzyme that catalyzes the chemical reaction

In enzymology, a nucleoside-phosphate kinase is an enzyme that catalyzes the chemical reaction

In enzymology, a phosphatidylinositol-4-phosphate 3-kinase is an enzyme that catalyzes the chemical reaction

In enzymology, a phosphoglucokinase is an enzyme that catalyzes the chemical reaction

In enzymology, a phosphoribokinase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Ribokinase</span>

In enzymology, a ribokinase is an enzyme that catalyzes the chemical reaction

In enzymology, a tagatose kinase is an enzyme that catalyzes the chemical reaction

Bisphosphate may refer to:

References