Literature summary for 2.7.1.46 extracted from

Behmueller, R.; Kavkova, E.; Dueh, S.; Huber, C.G.; Tenhaken, R.
The role of arabinokinase in arabinose toxicity in plants (2016), Plant J., 87, 376-390 .

Search for more literature for 2.7.1.46

Cloned(Commentary)

Cloned (Comment)	Organism
gene Ara2, transient expression of C-terminally Strep-tagged Ara2 in Nicotiana benthamiana leaves	Arabidopsis thaliana
recombinant expression of N-terminally GFP-tagged isozyme Ara1 in Nicotiana benthamiana in the cytosol of cells, transient expression of C-terminally Strep-tagged Ara1 in Nicotiana benthamiana leaves	Arabidopsis thaliana

Protein Variants

Protein Variants	Comment	Organism
E564K	a ara2-1 mutant form of the enzyme that carries a point mutation in an alpha-helix. The mutation is close to the substrate binding site. The residual enzymatic activity of ARAK2 mutant E564K is below 1% when compared with the wild-type ARAK2 variant. 227fold increase of Km value for L-arabinose for ARA2 E564K mutant compared to wild-type	Arabidopsis thaliana
E655K	an ara1-1 mutant form of the enzyme that carries a point mutation in an alpha-helix. Almost inactive mutant. The mutation is close to the substrate binding site and changes the Km value for arabinose from 0.08 mM in the wild-type to 17 mM in ARA1-1 mutant. Analysis of marker genes from sugar signalling pathways (SnRK1 and Tor) suggests that ara1-1 misinterprets its carbon energy status. Although glucose is present in ara1-1 similar to wild-type levels, it constitutively changes gene expression as typically found in wild-type plants only under starvation conditions. Furthermore, ara1-1 shows increased expression of marker genes for programmed cell death as found in other lesion mimic mutants	Arabidopsis thaliana
additional information	plants are knocked-out for arabinokinase by T-DNA insertion, the mutant KO plants accumulate higher levels of arabinose but do not show signs of arabinose toxicity. Creation of a double knockout plant ara1-2 ara2-1 double mutant by crossing the single knockout plants. 193fold increase of Km value for L-arabinose for ARA1-1 compared to wild-type. Infiltration of Nicotiana benthamiana leaves with ARA2 and ARA2-1 constructs showing first signs of necrosis after 3 days at the sites of infiltration. Arabinose feeding causes UDP-sugar changes in ara1-1 and wild-type (UDP-sugars: UDP-Ara, UDP-Xyl, UDP-Gal and UDP-Glc), and causes an increase in soluble carbohydrates in ara1-1	Arabidopsis thaliana
additional information	plants are knocked-out for arabinokinase by T-DNA insertion, the mutant KO plants accumulate higher levels of arabinose but do not show signs of arabinose toxicity. Creation of a double knockout plant ara1-2 ara2-1 double mutant by crossing the single knockout plants. Infiltration of Nicotiana benthamiana leaves with ARA2 and ARA2-1 constructs showing first signs of necrosis after 3 days at the sites of infiltration	Arabidopsis thaliana

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
additional information	-	additional information	kinetics, recombinant enzyme	Arabidopsis thaliana
0.005	-	ATP	pH 8.0, 30°C, Ara1	Arabidopsis thaliana
0.01	-	ATP	pH 6.5, 35°C, Ara2	Arabidopsis thaliana
0.079	-	L-arabinose	pH 6.5, 35°C, Ara2	Arabidopsis thaliana
0.088	-	L-arabinose	pH 8.0, 30°C, Ara1	Arabidopsis thaliana
17	-	L-arabinose	pH 8.0, 30°C, mutant ARA1-1	Arabidopsis thaliana
18	-	L-arabinose	pH 8.0, 30°C, ARA2 E564K mutant	Arabidopsis thaliana

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
cytosol	-	Arabidopsis thaliana	5829	-
cytosol	the potential N-terminal part of ARA1 is targeting the protein to specific cellular compartment. The 50 amino acid part of ARA1 is localized in the cytosol and not redirecting ARA1 into organelles	Arabidopsis thaliana	5829	-

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Co2+	activates	Arabidopsis thaliana
Mg2+	required	Arabidopsis thaliana
Mn2+	activates	Arabidopsis thaliana
additional information	magnesium, cobalt, or manganese are required to achieve product formation. The highest activity is obtained with magnesium as cofactor	Arabidopsis thaliana

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
100000	-	-	Arabidopsis thaliana

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + L-arabinose	Arabidopsis thaliana	-	ADP + beta-L-arabinose 1-phosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Arabidopsis thaliana	A0A1I9LRU1	-	-
Arabidopsis thaliana	O23461	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + L-arabinose	-	Arabidopsis thaliana	ADP + beta-L-arabinose 1-phosphate	-	?
ATP + L-arabinose	arabinokinase has a high affinity for L-arabinose	Arabidopsis thaliana	ADP + beta-L-arabinose 1-phosphate	-	?
additional information	substrate specificity, overview. Arabinokinase has a high affinity for L-arabinose. No activity with D-galacturonic acid, L-rhamnose, D-glucose, D-mannose, D-arabinose, D-glucuronic acid, D-xylose, and D-galactose	Arabidopsis thaliana	?	-	-
additional information	substrate specificity, overview. Arabinokinase has a high affinity for L-arabinose. No activity with D-galacturonic acid, L-rhamnose, D-glucose, D-mannose, D-arabinose, L-arabinose, D-glucuronic acid, D-xylose, and D-galactose	Arabidopsis thaliana	?	-	-

Subunits

Subunits	Comment	Organism
More	the 100 kDA enzyme protein contains a putative N-terminal glycosyltransferase domain and a C-terminal sugar-1-kinase domain. This unique structure is highly conserved in the plant kingdom. The gene coding for ARA2, unlike ARA1, does not contain any potential signal sequence at the N-terminus	Arabidopsis thaliana

Synonyms

Synonyms	Comment	Organism
ARA1	-	Arabidopsis thaliana
ARA2	-	Arabidopsis thaliana
arabinokinase	-	Arabidopsis thaliana
At3g42850	locus name	Arabidopsis thaliana
At4g16130	locus name	Arabidopsis thaliana
mevalonate/galactokinase family protein	UniProt	Arabidopsis thaliana

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
30	-	-	Arabidopsis thaliana
35	-	-	Arabidopsis thaliana

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
6.5	-	-	Arabidopsis thaliana
8	-	-	Arabidopsis thaliana

General Information

General Information	Comment	Organism
evolution	arabinokinase is a GHMP (galactose, homoserine, mevalonate, phosphomevalonate) kinase with a unique structure that is highly conserved in plants. Isozymes Ara1 and Ara2 share 71% amino acid identity	Arabidopsis thaliana
malfunction	exogenous L-arabinose and its cellular accumulation are lethal for the point mutation variant ara1-1. Ara1-1 displays a lethal phenotype only upon L-arabinose treatment. The amino acid exchange of ARA1-1 is part of a conserved alpha-helix. The mutation borders a SSSAA motif which is present in both kinases and plays a role in creating the binding pocket surface. The model and alignments of both proteins show that the amino acid exchange site is closely located at the entrance of the substrate binding pocket. Recombinant Nicotiana benthamiana leaves infiltrated with ARA1 and ARA1-1 constructs show first signs of necrosis after 3 days at the sites of infiltration	Arabidopsis thaliana
malfunction	exogenous L-arabinose and its cellular accumulation are not lethal for the ara1-2 knockout plant. Recombinant Nicotiana benthamiana leaves infiltrated with ARA2 and ARA2-1 constructs show first signs of necrosis after 3 days at the sites of infiltration	Arabidopsis thaliana
physiological function	role of arabinokinase in arabinose toxicity in plants	Arabidopsis thaliana

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Release 2023.1 (January 2023)