Catalytic reaction of cytokinin dehydrogenase: preference for quinones as electron acceptors
Frebortova, J.; Fraaije, M.W.; Galuszka, P.; Sebela, M.; Pec, P.; Hrbac, J.; Novak, O.; Bilyeu, K.D.; English, J.T.; Frebort, I.; Biochem. J. 380, 121-130 (2004) 
Data extracted from this reference:
Cloned(Commentary)
EC Number
Cloned (Commentary)
Organism
1.5.99.12
expression of ZmCKX1 in Pichia pastoris
Zea mays
KM Value [mM]
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.5.99.12
additional information
-
additional information
kinetics, redox potential of electron acceptors
Zea mays
Natural Substrates/ Products (Substrates)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
ID
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
Zea mays
the natural terminal electron acceptor probably is a p-quinone or a similar compound, high substrate specificity for N6-(2-isopentenyl)adenine
adenine + 3-methylbut-2-enal + FADH2
-
-
?
Organism
EC Number
Organism
UniProt
Commentary
Textmining
1.5.99.12
Zea mays
Q9T0N8
enzyme and gene ZmCKX1
-
Reaction
EC Number
Reaction
Commentary
Organism
Reaction ID
1.5.99.12
N6-dimethylallyladenine + acceptor + H2O = adenine + 3-methylbut-2-enal + reduced acceptor
reaction scheme and mechanism, reduction of N6-(2-isopentenyl)adenine is rapidly performed, the reaction with O2 is slowly
Zea mays
Substrates and Products (Substrate)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
Substrate Product ID
1.5.99.12
additional information
substrate specificity with cytokinins, overiew
654539
Zea mays
?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 1,4-naphthoquinone
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 1,4-naphthoquinone
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 2,3-dimethoxy-5-methyl-1,4-benzoquinone
i.e. coenzyme Q0
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 2,3-dimethoxy-5-methyl-1,4-benzoquinone
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 2,6-dichlorophenolindophenol
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 2,6-dichlorophenolindophenol
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + caffeic acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + coenzyme Q1
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced coenzyme Q1
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + cytochrome c
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced cytochrome c
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + daphnoretin
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
-
654539
Zea mays
adenine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
the natural terminal electron acceptor probably is a p-quinone or a similar compound, high substrate specificity for N6-(2-isopentenyl)adenine
654539
Zea mays
adenine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + o-coumaric acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + O2
oxidative degradation of cytokinins, slow reaction, low substrate specificity
654539
Zea mays
adenine + 3-methylbut-2-enal + H2O2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + plantacyanine
electron acceptor from spinach
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced plantacyanine
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + rosmarinic acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + scopoletin
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + spinach plantacyanine
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced spinach plantacyanine
-
-
-
r
1.5.99.12
N6-(2-isopentenyl)adenine + vitamin K1
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced vitamin K1
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + vitamin K3
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced vitamin K3
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenosine + FAD
-
654539
Zea mays
adenosine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
zeatin + FAD
-
654539
Zea mays
? + FADH2
-
-
-
?
Synonyms
EC Number
Synonyms
Commentary
Organism
1.5.99.12
CKX
-
Zea mays
1.5.99.12
cytokinin oxidase/dehydrogenase
-
Zea mays
1.5.99.12
More
enzyme belongs to the plant CKX family
Zea mays
Turnover Number [1/s]
EC Number
Turnover Number Minimum [1/s]
Turnover Number Maximum [1/s]
Substrate
Commentary
Organism
Structure
1.5.99.12
additional information
-
additional information
at pH above pH 6.5 polymerization of the quinone acceptors occur
Zea mays
1.5.99.12
0.1
-
O2
below, pH 8.0, recombinant enzyme
Zea mays
1.5.99.12
0.3
-
caffeic acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.3
-
o-coumaric acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.4
-
rosmarinic acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.6
-
O2
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.8
-
cytochrome c
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.9
-
spinach plantacyanine
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
1
-
daphnoretin
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
1.4
-
scopoletin
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
2.3
-
vitamin K1
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
85.4
-
vitamin K3
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
123.1
-
coenzyme Q1
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
129.8
-
N6-(2-isopentenyl)adenosine
pH 6.5, recombinant enzyme, with cofactor 2,3-dimethoxy-5-methyl-1,4-benzoquinone
Zea mays
1.5.99.12
143.6
-
2,3-dimethoxy-5-methyl-1,4-benzoquinone
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
143.6
-
N6-(2-isopentenyl)adenine
pH 6.5, recombinant enzyme, with cofactor 2,3-dimethoxy-5-methyl-1,4-benzoquinone
Zea mays
1.5.99.12
169.6
-
1,4-Naphthoquinone
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
178.4
-
2,6-dichlorophenolindophenol
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
278
-
2,6-dichlorophenolindophenol
pH 8.0, recombinant enzyme
Zea mays
pH Optimum
EC Number
pH Optimum Minimum
pH Optimum Maximum
Commentary
Organism
1.5.99.12
additional information
-
substrate-dependent pH-profile, overview
Zea mays
Cofactor
EC Number
Cofactor
Commentary
Organism
Structure
1.5.99.12
FAD
covalently bound, redox potential analysis
Zea mays
1.5.99.12
additional information
enzyme shows a preference for quinones as electron acceptors
Zea mays
Cloned(Commentary) (protein specific)
EC Number
Commentary
Organism
1.5.99.12
expression of ZmCKX1 in Pichia pastoris
Zea mays
Cofactor (protein specific)
EC Number
Cofactor
Commentary
Organism
Structure
1.5.99.12
FAD
covalently bound, redox potential analysis
Zea mays
1.5.99.12
additional information
enzyme shows a preference for quinones as electron acceptors
Zea mays
KM Value [mM] (protein specific)
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.5.99.12
additional information
-
additional information
kinetics, redox potential of electron acceptors
Zea mays
Natural Substrates/ Products (Substrates) (protein specific)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
ID
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
Zea mays
the natural terminal electron acceptor probably is a p-quinone or a similar compound, high substrate specificity for N6-(2-isopentenyl)adenine
adenine + 3-methylbut-2-enal + FADH2
-
-
?
Substrates and Products (Substrate) (protein specific)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
ID
1.5.99.12
additional information
substrate specificity with cytokinins, overiew
654539
Zea mays
?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 1,4-naphthoquinone
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 1,4-naphthoquinone
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 2,3-dimethoxy-5-methyl-1,4-benzoquinone
i.e. coenzyme Q0
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 2,3-dimethoxy-5-methyl-1,4-benzoquinone
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + 2,6-dichlorophenolindophenol
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced 2,6-dichlorophenolindophenol
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + caffeic acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + coenzyme Q1
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced coenzyme Q1
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + cytochrome c
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced cytochrome c
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + daphnoretin
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
-
654539
Zea mays
adenine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + FAD
the natural terminal electron acceptor probably is a p-quinone or a similar compound, high substrate specificity for N6-(2-isopentenyl)adenine
654539
Zea mays
adenine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + o-coumaric acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + O2
oxidative degradation of cytokinins, slow reaction, low substrate specificity
654539
Zea mays
adenine + 3-methylbut-2-enal + H2O2
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + plantacyanine
electron acceptor from spinach
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced plantacyanine
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + rosmarinic acid
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + scopoletin
-
654539
Zea mays
adenine + 3-methylbut-2-enal + ?
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + spinach plantacyanine
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced spinach plantacyanine
-
-
-
r
1.5.99.12
N6-(2-isopentenyl)adenine + vitamin K1
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced vitamin K1
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenine + vitamin K3
-
654539
Zea mays
adenine + 3-methylbut-2-enal + reduced vitamin K3
-
-
-
?
1.5.99.12
N6-(2-isopentenyl)adenosine + FAD
-
654539
Zea mays
adenosine + 3-methylbut-2-enal + FADH2
-
-
-
?
1.5.99.12
zeatin + FAD
-
654539
Zea mays
? + FADH2
-
-
-
?
Turnover Number [1/s] (protein specific)
EC Number
Turnover Number Minimum [1/s]
Turnover Number Maximum [1/s]
Substrate
Commentary
Organism
Structure
1.5.99.12
additional information
-
additional information
at pH above pH 6.5 polymerization of the quinone acceptors occur
Zea mays
1.5.99.12
0.1
-
O2
below, pH 8.0, recombinant enzyme
Zea mays
1.5.99.12
0.3
-
caffeic acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.3
-
o-coumaric acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.4
-
rosmarinic acid
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.6
-
O2
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.8
-
cytochrome c
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
0.9
-
spinach plantacyanine
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
1
-
daphnoretin
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
1.4
-
scopoletin
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
2.3
-
vitamin K1
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
85.4
-
vitamin K3
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
123.1
-
coenzyme Q1
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
129.8
-
N6-(2-isopentenyl)adenosine
pH 6.5, recombinant enzyme, with cofactor 2,3-dimethoxy-5-methyl-1,4-benzoquinone
Zea mays
1.5.99.12
143.6
-
2,3-dimethoxy-5-methyl-1,4-benzoquinone
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
143.6
-
N6-(2-isopentenyl)adenine
pH 6.5, recombinant enzyme, with cofactor 2,3-dimethoxy-5-methyl-1,4-benzoquinone
Zea mays
1.5.99.12
169.6
-
1,4-Naphthoquinone
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
178.4
-
2,6-dichlorophenolindophenol
pH 6.5, recombinant enzyme
Zea mays
1.5.99.12
278
-
2,6-dichlorophenolindophenol
pH 8.0, recombinant enzyme
Zea mays
pH Optimum (protein specific)
EC Number
pH Optimum Minimum
pH Optimum Maximum
Commentary
Organism
1.5.99.12
additional information
-
substrate-dependent pH-profile, overview
Zea mays