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Literature summary for 2.7.4.26 extracted from

  • Henry, L.K.; Gutensohn, M.; Thomas, S.T.; Noel, J.P.; Dudareva, N.
    Orthologs of the archaeal isopentenyl phosphate kinase regulate terpenoid production in plants (2015), Proc. Natl. Acad. Sci. USA, 112, 10050-10055.
    View publication on PubMedView publication on EuropePMC
Search for more literature for 2.7.4.26

Cloned(Commentary)

Cloned (Comment) Organism
gene ipk2, analysis of genes coexpressing with AtIPK, At1g26640, overview. Overexpression of gene ipk1 in transgenic tobacco plants Arabidopsis thaliana

Protein Variants

Protein Variants Comment Organism
additional information generation of two Arabidopsis T-DNA insertion lines (ipk1, ipk2) by reverse genetics. Quantitative RT-PCR (qRT-PCR) expression analysis with two sets of gene-specific primers, one located upstream of T-DNA insertions and the other downstream near the 3' end of the gene. No AtIPK transcripts are detected in ipk1, whereas transcript levels are reduced by 83% in ipk2, with remaining expression likely a result of residual splicing despite the intron-localized T-DNA insertion. Both ipk1 and ipk2 seedlings show a significant decrease in campesterol and sitosterol content (50% and 37% of wild-type, respectively), while the stigmasterol levels are unchanged Arabidopsis thaliana

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.032
-
 isopentenyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
0.033
-
 dimethylallyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
0.22
-
 geranyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana

Localization

Localization Comment Organism GeneOntology No. Textmining
cytosol
-
 Arabidopsis thaliana 5829
-
additional information not in chloroplasts Arabidopsis thaliana
-
-

Metals/Ions

Metals/Ions Comment Organism Structure
Mg2+ required Arabidopsis thaliana

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ATP + dimethylallyl phosphate Arabidopsis thaliana
-
 ADP + dimethylallyl diphosphate
-
 ?
ATP + geranyl phosphate Arabidopsis thaliana low activity ADP + geranyl diphosphate
-
 ?
ATP + isopentenyl phosphate Arabidopsis thaliana
-
 ADP + isopentenyl diphosphate
-
 ?

Organism

Organism UniProt Comment Textmining
Arabidopsis thaliana Q8H1F7 IPK2; gene IPK2
-

Source Tissue

Source Tissue Comment Organism Textmining
leaf
-
 Arabidopsis thaliana
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + dimethylallyl phosphate
-
 Arabidopsis thaliana ADP + dimethylallyl diphosphate
-
 ?
ATP + geranyl phosphate low activity Arabidopsis thaliana ADP + geranyl diphosphate
-
 ?
ATP + isopentenyl phosphate
-
 Arabidopsis thaliana ADP + isopentenyl diphosphate
-
 ?

Synonyms

Synonyms Comment Organism
Ipk2
-
 Arabidopsis thaliana
isopentenyl phosphate kinase
-
 Arabidopsis thaliana

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.0039
-
 geranyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
2.7
-
 dimethylallyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
3.7
-
 isopentenyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana

Cofactor

Cofactor Comment Organism Structure
ATP
-
 Arabidopsis thaliana

General Information

General Information Comment Organism
malfunction AtIPK knockout or knockdown affects formation of two of the three predominant Arabidopsis sterols. Similar sterol levels in knockout (ipk1) and knockdown (ipk2) mutants indicate that remaining AtIPK expression in ipk2 supports only marginal flux toward IPP/DMAPP formation without increasing downstream terpenoid production relative to the null ipk knockout. The lack of reduction in stigmasterol levels suggests that the reduced pool of sitosterol, the immediate precursor of stigmasterol, is still sufficient to sustain unaltered production of the latter. In addition, emission of beta-caryophyllene, the most abundant sesquiterpene compound in Arabidopsis is reduced by 25-31% in flowers of ipk mutants compared with wild-type Arabidopsis thaliana
metabolism the enzyme is involved in the isopentenyl phosphate kinase pathway. The absence of two components of the mevalonate (MVA) pathway from archaeal genomes leads to the discovery of an alternative mevalonate pathway with isopentenyl phosphate kinase (IPK) catalyzing the final step, the formation of isopentenyl diphosphate. Despite the fact that plants contain the complete classical mevalonate pathway, IPK homologues are identified in every sequenced green plant genome. Position and potential role of IPK in the plant terpenoid metabolic network, overview Arabidopsis thaliana
physiological function IPK may be functionally connected to the mevalonate (MVA) pathway and biosynthesis of downstream terpenoids, including sesquiterpenes, triterpenes, and sterols. Enzyme IPK catalyzes the final step in the formation of isopentanyl diphosphate. Plants IPK plays a role in modulating the formation and pool sizes of farnesyl diphosphate-derived terpenoids. IPK also contributes to formation of geranyl diphosphate-derived terpenoids in plastids Arabidopsis thaliana

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
0.018
-
 geranyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
85
-
 dimethylallyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana
101
-
 isopentenyl phosphate pH and temperature not specified in the publication Arabidopsis thaliana