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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
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MetaCyc Reaction: 2.7.4.21/2.7.4.24

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number: 2.7.4.21 , 2.7.4.24

Enzymes and Genes:
inositol hexakisphosphate kinase 2 Inferred from experiment : IP6K2 ( Homo sapiens )
inositol hexakisphosphate kinase 3 Inferred from experiment : IP6K3 ( Homo sapiens )
inositol hexakisphosphate kinase 1 Inferred from experiment : IP6K1 ( Homo sapiens )

In Pathway: inositol pyrophosphates biosynthesis

Supersedes EC numbers: 2.7.1.152, 2.7.1.155

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

Mass balance status: Balanced.

Direct generic reaction:
ATP + a diphospho-1D-myo-inositol pentakisphosphate = ADP + a bis(diphospho)-1D-myo-inositol tetrakisphosphate (2.7.4.-)

Enzyme Commission Primary Name for 2.7.4.21: inositol-hexakisphosphate kinase

Enzyme Commission Synonyms for 2.7.4.21: ATP:1D-myo-inositol-hexakisphosphate phosphotransferase, IP6K

Enzyme Commission Primary Name for 2.7.4.24: diphosphoinositol-pentakisphosphate kinase

Enzyme Commission Synonyms for 2.7.4.24: PP-IP5 kinase, diphosphoinositol pentakisphosphate kinase, ATP:5-diphospho-1D-myo-inositol-pentakisphosphate phosphotransferase, PP-InsP5 kinase, PPIP5K, PPIP5K1, PPIP5K2, VIP1, VIP2

Standard Gibbs Free Energy (ΔrG in kcal/mol): -7.0270996 Inferred by computational analysis [Latendresse13]

Summary:
Formerly EC 2.7.1.155.

Enzyme Commission Summary for 2.7.4.21:
This reaction is considered a second official reaction for EC 2.7.4.21.

Three mammalian isoforms are known to exist.

Enzyme Commission Summary for 2.7.4.24:
This enzyme is activated by osmotic shock. D-myo-inositol 1,3,4,5,6-pentakisphosphate, 1D-myo-inositol 1,5-bis(diphosphate) 2,3,4,6-tetrakisphosphate and 1D-myo-inositol bisdiphosphate triphosphate are not substrates [Choi07].

Citations: [Lin09a, Saiardi99, Schell99, Albert97, Wang12d, Shears95, Fridy07]

Gene-Reaction Schematic: ?

Relationship Links: BRENDA:EC:2.7.4.21 , BRENDA:EC:2.7.4.24 , ENZYME:EC:2.7.4.21 , ENZYME:EC:2.7.4.24 , IUBMB-ExplorEnz:EC:2.7.4.21 , IUBMB-ExplorEnz:EC:2.7.4.24

Credits:
Created 29-Oct-2009 by Caspi R , SRI International


References

Albert97: Albert C, Safrany ST, Bembenek ME, Reddy KM, Reddy K, Falck J, Brocker M, Shears SB, Mayr GW (1997). "Biological variability in the structures of diphosphoinositol polyphosphates in Dictyostelium discoideum and mammalian cells." Biochem J 327 ( Pt 2);553-60. PMID: 9359429

Choi07: Choi JH, Williams J, Cho J, Falck JR, Shears SB (2007). "Purification, sequencing, and molecular identification of a mammalian PP-InsP5 kinase that is activated when cells are exposed to hyperosmotic stress." J Biol Chem 282(42);30763-75. PMID: 17702752

Fridy07: Fridy PC, Otto JC, Dollins DE, York JD (2007). "Cloning and characterization of two human VIP1-like inositol hexakisphosphate and diphosphoinositol pentakisphosphate kinases." J Biol Chem 282(42);30754-62. PMID: 17690096

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Lin09a: Lin H, Fridy PC, Ribeiro AA, Choi JH, Barma DK, Vogel G, Falck JR, Shears SB, York JD, Mayr GW (2009). "Structural analysis and detection of biological inositol pyrophosphates reveal that the family of VIP/diphosphoinositol pentakisphosphate kinases are 1/3-kinases." J Biol Chem 284(3);1863-72. PMID: 18981179

Saiardi99: Saiardi A, Erdjument-Bromage H, Snowman AM, Tempst P, Snyder SH (1999). "Synthesis of diphosphoinositol pentakisphosphate by a newly identified family of higher inositol polyphosphate kinases." Curr Biol 9(22);1323-6. PMID: 10574768

Schell99: Schell MJ, Letcher AJ, Brearley CA, Biber J, Murer H, Irvine RF (1999). "PiUS (Pi uptake stimulator) is an inositol hexakisphosphate kinase." FEBS Lett 461(3);169-72. PMID: 10567691

Shears95: Shears SB, Ali N, Craxton A, Bembenek ME (1995). "Synthesis and metabolism of bis-diphosphoinositol tetrakisphosphate in vitro and in vivo." J Biol Chem 270(18);10489-97. PMID: 7737983

Wang12d: Wang H, Falck JR, Hall TM, Shears SB (2012). "Structural basis for an inositol pyrophosphate kinase surmounting phosphate crowding." Nat Chem Biol 8(1);111-6. PMID: 22119861


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Wed Nov 26, 2014, biocyc13.