Reaction participants Show >> << Hide
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Name help_outline
polyphosphate
Identifier
CHEBI:16838
Charge
Formula
(O3P)nHO
Search links
Involved in 10 reaction(s)
Find proteins in UniProtKB for this molecule
Form(s) in this reaction:
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Identifier: RHEA-COMP:9859Polymer name: [phosphate](n)Polymerization index help_outline nFormula HO(O3P)nCharge (-1)(-1)nMol File for the polymer
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Identifier: RHEA-COMP:14279Polymer name: [phosphate](n-1)Polymerization index help_outline n-1Formula HO(O3P)n-1Charge (-1)(-1)n-1Mol File for the polymer
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- Name help_outline D-glucose Identifier CHEBI:4167 (Beilstein: 1281604; CAS: 2280-44-6) help_outline Charge 0 Formula C6H12O6 InChIKeyhelp_outline WQZGKKKJIJFFOK-GASJEMHNSA-N SMILEShelp_outline OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 161 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline D-glucose 6-phosphate Identifier CHEBI:61548 Charge -2 Formula C6H11O9P InChIKeyhelp_outline NBSCHQHZLSJFNQ-GASJEMHNSA-L SMILEShelp_outline OC1O[C@H](COP([O-])([O-])=O)[C@@H](O)[C@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 32 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 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:22036 | RHEA:22037 | RHEA:22038 | RHEA:22039 | |
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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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Kinetic mechanisms of polyphosphate glucokinase from Mycobacterium tuberculosis.
Hsieh P.C., Kowalczyk T.H., Phillips N.F.
Polyphosphate glucokinase from Mycobacterium tuberculosis catalyzes the phosphorylation of glucose using inorganic polyphosphates [poly(P)] or ATP. The steady-state kinetic mechanisms of the poly(P)- and ATP-dependent glucokinase reactions were investigated using initial velocity, product inhibiti ... >> More
Polyphosphate glucokinase from Mycobacterium tuberculosis catalyzes the phosphorylation of glucose using inorganic polyphosphates [poly(P)] or ATP. The steady-state kinetic mechanisms of the poly(P)- and ATP-dependent glucokinase reactions were investigated using initial velocity, product inhibition, and dead-end inhibition analyses. In the poly(P)-dependent reaction, the enzyme follows an Ordered Bi Bi sequential mechanism with poly(P) binding to the enzyme first and glucose 6-phosphate dissociating last. Polyphosphate is utilized nonprocessively with a preference for longer chains due to higher kcat/K(m) values. The lack of inhibition at high poly(P) concentrations suggests that binding of poly(P) as a product is not favorable. In the ATP-dependent glucokinase reaction, the data are also consistent with an Ordered Bi Bi sequential mechanism, with ATP binding to the enzyme first and glucose 6-phosphate leaving last. At high concentrations, ATP displays competitive substrate inhibition with respect to glucose, which is consistent with the formation of an enzyme.ATP.ATP nonproductive complex. The overall catalytic efficiencies (kcat/KiaK(b)) of the poly(P)- and ATP-dependent reactions are approximately 10(11) M-2 s-1 and approximately 10(8) M-2 s-1, respectively. The higher catalytic efficiency, high value of the substrate specificity constant (kcat/K(a)) approaching a diffusion-controlled limit, and the absence of substrate inhibition in the poly(P)-dependent reaction suggest that poly(P), rather than ATP, is the major phosphate donor for poly(P)-glucokinase in M. tuberculosis. << Less
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Polyphosphate glucokinase from Propionibacterium shermanii. Kinetics and demonstration that the mechanism involves both processive and nonprocessive type reactions.
Pepin C.A., Wood H.G.
Polyphosphate glucokinase (EC 2.7.1.63, polyphosphate glucose phosphotransferase) has been partially purified (960-fold) from Propionibacterium shermanii. Throughout the purification, the ratio of polyphosphate glucokinase activity to ATP glucokinase activity remained approximately constant at 4 t ... >> More
Polyphosphate glucokinase (EC 2.7.1.63, polyphosphate glucose phosphotransferase) has been partially purified (960-fold) from Propionibacterium shermanii. Throughout the purification, the ratio of polyphosphate glucokinase activity to ATP glucokinase activity remained approximately constant at 4 to 1. It is considered that both activities are catalyzed by the same protein. The mechanism of utilization of polyphosphate by polyphosphate glucokinase was investigated using polyphosphates of limited sizes that were isolated following gel electrophoresis of commercial heterogeneous polyphosphates. The results show that with long chain polyphosphates, the reaction proceeds by a processive type mechanism, and with short polyphosphates, it is nonprocessive. The Km for polyphosphate of chain length 724 is 2 X 10(-3) microM and increases with a decrease in chain length to 3.7 X 10(-2) microM at chain length 138. Subsequently, there is a very rapid increase of Km and at chain length 30 the Km is 4.3 microM. The rapid change in Km coincides with the shift in mechanism from the processive type mechanism in which there apparently is successive phosphorylation prior to release from the enzyme to a nonprocessive process in which the polyphosphate is released from the enzyme after each transfer. During the nonprocessive process, there is preferential utilization of the longer species. The Vmax is relatively constant with shorter polyphosphates but decreases with chain lengths longer than 347. In the cell, as a consequence of the low Km, the long chain polyphosphates probably are used preferentially to phosphorylate glucose. << Less
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Crystal structure of bacterial inorganic polyphosphate/ATP-glucomannokinase. Insights into kinase evolution.
Mukai T., Kawai S., Mori S., Mikami B., Murata K.
Inorganic polyphosphate (poly(P)) is a biological high energy compound presumed to be an ancient energy carrier preceding ATP. Several poly(P)-dependent kinases that use poly(P) as a phosphoryl donor are known to function in bacteria, but crystal structures of these kinases have not been solved. H ... >> More
Inorganic polyphosphate (poly(P)) is a biological high energy compound presumed to be an ancient energy carrier preceding ATP. Several poly(P)-dependent kinases that use poly(P) as a phosphoryl donor are known to function in bacteria, but crystal structures of these kinases have not been solved. Here we present the crystal structure of bacterial poly(P)/ATP-glucomannokinase, belonging to Gram-positive bacterial glucokinase, complexed with 1 glucose molecule and 2 phosphate molecules at 1.8 A resolution, being the first among poly(P)-dependent kinases and bacterial glucokinases. The poly(P)/ATP-glucomannokinase structure enabled us to understand the structural relationship of bacterial glucokinase to eucaryotic hexokinase and ADP-glucokinase, which has remained a matter of debate. These comparisons also enabled us to propose putative binding sites for phosphoryl groups for ATP and especially for poly(P) and to obtain insights into the evolution of kinase, particularly from primordial poly(P)-specific to ubiquitous ATP-specific proteins. << Less