Information on EC 4.2.3.27 - isoprene synthase

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The expected taxonomic range for this enzyme is: Eukaryota, Bacteria

EC NUMBER
COMMENTARY
4.2.3.27
-
RECOMMENDED NAME
GeneOntology No.
isoprene synthase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
dimethylallyl diphosphate = isoprene + diphosphate
show the reaction diagram
-
-
-
-
dimethylallyl diphosphate = isoprene + diphosphate
show the reaction diagram
the generation of isoprene from substrate dimethylallyl diphosphate occurs via a syn-periplanar elimination mechanism in which the diphosphate-leaving group serves as a general base
-, Q9AR86
PATHWAY
KEGG Link
MetaCyc Link
Biosynthesis of secondary metabolites
-
isoprene biosynthesis I
-
isoprene biosynthesis II (engineered)
-
Terpenoid backbone biosynthesis
-
SYSTEMATIC NAME
IUBMB Comments
dimethylallyl-diphosphate diphosphate-lyase (isoprene-forming)
Requires Mg2+ or Mn2+ for activity. This enzyme is located in the chloroplast of isoprene-emitting plants, such as poplar and aspen, and may be activitated by light-dependent changes in chloroplast pH and Mg2+ concentration [2,8].
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
isoprene synthase
-
-
isoprene synthase
-
-
isoprene synthase
-
-
isoprene synthase
A9Q7C9
-
isoprene synthase
D8UY75, D8UY76
-
isoprene synthase
Q50L36
-
isoprene synthase
A0PFK2
-
isoprene synthase
-
-
isoprene synthase
-
-
isoprene synthase
-
-
isoprene synthase
Q6EJ97
-
ISPS
-
-
ISPS
Q50L36
-
ISPS
A0PFK2
-
ispS3
D8UY76
gene name
PnISPS
A0PFK2
-
CAS REGISTRY NUMBER
COMMENTARY
139172-14-8
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
transgenic, transformend with Grey poplar ISPS
-
-
Manually annotated by BRENDA team
strain 6051
-
-
Manually annotated by BRENDA team
Bacillus subtilis 6051
strain 6051
-
-
Manually annotated by BRENDA team
var. utilis
-
-
Manually annotated by BRENDA team
Mucuna sp.
velvet bean
-
-
Manually annotated by BRENDA team
-
SwissProt
Manually annotated by BRENDA team
gene ispS; gene ispS
SwissProt
Manually annotated by BRENDA team
gene name ispS3
UniProt
Manually annotated by BRENDA team
hybrid, Populus tremula x Populus tremuloides
-
-
Manually annotated by BRENDA team
penduculate oak
-
-
Manually annotated by BRENDA team
soluble and membrane-bound isozymes
-
-
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q7XAS7
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-, Q50L36
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q50L36
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q9AR86
-
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
isoprene is emitted into the atmosphere following a diurnal cycle in vivo
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
isoprene is emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Mucuna sp.
-
-
isoprene is emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
i.e. 2-methyl-1,3-butadiene
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
i.e. 2-methyl-1,3-butadiene
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q9AR86
-
i.e. 2-methyl-1,3-butadiene
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Mucuna sp.
-
-
i.e. 2-methyl-1,3-butadiene
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
i.e. 2-methyl-1,3-butadiene, product determination by gas chromatography
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
i.e. 2-methyl-1,3-butadiene, product determination by gas chromatography
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
i.e. 2-methyl-1,3-butadiene, volatile product, product determination by gas chromatography
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
product stoichiometry determination, isoprene is volatile 2-methyl-1,3-butadiene emitted by the plant into the atmosphere, where it plays an important role, the enzyme is positively regulated by light
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
A9Q7C9
-
isoprene (2-methyl-1,3-butadiene) emission represents a significant loss of carbon to those plant species that synthesize this highly volatile and reactive compound, isoprene has major impacts on atmospheric chemistry
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
A0PFK2, -
-
isoprene is an important molecule for ameliorating abiotic stresses
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
in presence of a divalent cation
-
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
light- and age-dependent regulation of the thylakoid membrane-bound enzyme, the relation of soluble and membrane-bound isozymes is not affected by light and leaf age, overview
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
light-dependent regulation of the thylakoid membrane-bound enzyme, overview
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
substrate limitations can be responsible for great variations of enzyme activity from leaf to leaf, substrate limitations can be responsinsible for great variations of enzyme activity from leaf to leaf
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
the enzyme is positively regulated by light
isoprene is emitted into the atmosphere following a diurnal cycle in vivo
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-, Q50L36
the enzyme is absolutely specific for dimethylally diphosphate
product identification
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
the control on foliar isoprene emission is shared between the activity of isoprene synthase, the terminal enzyme catalyzing isoprene formation from dimethylallyl diphosphate and the pool size of dimethyl allyldiphosphate
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
D8UY76
isoprene is produced via the methyl erythritol pathway from recently assimilated carbon
-
-
-
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Bacillus subtilis 6051
-
in presence of a divalent cation
-
-
ir
additional information
?
-
-
the acid-catalyzed non-enzymatic conversion of dimethylallyl diphosphate is negligible at physiologic pH
-
-
-
additional information
?
-
-
the enzyme activity parallels fluctuations of isoprene release during growth of Bacillus subtilis and is highly regulated, overview
-
-
-
additional information
?
-
-, Q50L36
substrate specifcity, no enzymatic activity with isoprenyl diphosphate or geranyl diphosphate as substrates, overview
-
-
-
additional information
?
-
-
dimethylallyl diphosphate pool is directly associated with isoprene synthesis
-
-
-
additional information
?
-
Bacillus subtilis 6051
-
the enzyme activity parallels fluctuations of isoprene release during growth of Bacillus subtilis and is highly regulated, overview
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q7XAS7
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-, Q50L36
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q50L36
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Q9AR86
-
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
isoprene is emitted into the atmosphere following a diurnal cycle in vivo
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
-
isoprene is emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Mucuna sp.
-
-
isoprene is emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
A9Q7C9
-
isoprene (2-methyl-1,3-butadiene) emission represents a significant loss of carbon to those plant species that synthesize this highly volatile and reactive compound, isoprene has major impacts on atmospheric chemistry
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
A0PFK2, -
-
isoprene is an important molecule for ameliorating abiotic stresses
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
in presence of a divalent cation
-
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
light- and age-dependent regulation of the thylakoid membrane-bound enzyme, the relation of soluble and membrane-bound isozymes is not affected by light and leaf age, overview
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
light-dependent regulation of the thylakoid membrane-bound enzyme, overview
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
substrate limitations can be responsible for great variations of enzyme activity from leaf to leaf, substrate limitations can be responsinsible for great variations of enzyme activity from leaf to leaf
isoprene is a volatile product emmitted to the atmosphere
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
the enzyme is positively regulated by light
isoprene is emitted into the atmosphere following a diurnal cycle in vivo
-
ir
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
-
the control on foliar isoprene emission is shared between the activity of isoprene synthase, the terminal enzyme catalyzing isoprene formation from dimethylallyl diphosphate and the pool size of dimethyl allyldiphosphate
-
-
?
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
D8UY76
isoprene is produced via the methyl erythritol pathway from recently assimilated carbon
-
-
-
dimethylallyl diphosphate
isoprene + diphosphate
show the reaction diagram
Bacillus subtilis 6051
-
in presence of a divalent cation
-
-
ir
additional information
?
-
-
the acid-catalyzed non-enzymatic conversion of dimethylallyl diphosphate is negligible at physiologic pH
-
-
-
additional information
?
-
-
the enzyme activity parallels fluctuations of isoprene release during growth of Bacillus subtilis and is highly regulated, overview
-
-
-
additional information
?
-
-
dimethylallyl diphosphate pool is directly associated with isoprene synthesis
-
-
-
additional information
?
-
Bacillus subtilis 6051
-
the enzyme activity parallels fluctuations of isoprene release during growth of Bacillus subtilis and is highly regulated, overview
-
-
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
Ca2+
Mucuna sp.
-
stimulates at up to 2 mM, inhibits at 2-30 mM
Co2+
-, Q50L36
activates, 23% of the activity with Mg2+
Fe2+
-, Q50L36
2% of the activity with Mg2+
Mg2+
-
activates at low concentration below 0.1 mM, inhibits at higher concentrations
Mg2+
-
the enzyme is strictly dependent on divalent cations, Mg2+ is the most effective
Mg2+
-, Q50L36
activates at 20 mM, best divalent cation
Mg2+
-
dependent on
Mg2+
Mucuna sp.
-
dependent on, best at 15 mM, 20fold higher activity compared to Mn2+
Mg2+
-
dependent on, optimal at 10-15 mM, activity profile at 0-25 mM MgCl2
Mg2+
-
dependent on, isozyme activity profiles, optimal at 10-20 mM
Mg2+
-
dependent on
Mg2+
Q9AR86
dependent on, the enzyme contains the Mg2+-binding DDXXD motif, typical for monoterpene synthases
Mg2+
-
dependent on, optimal at 20 mM
Mg2+
Q50L36
-
Mg2+
-
included in assay medium
Mg2+
-, Q9AR86
the metal binding motifs of ISPS interact with a trinuclear magnesium cluster in the complex with substrate dimethylallyl diphosphate. While Mg2+A is bound with full occupancy, the occupancies of Mg2+B and Mg2+C are each estimated to be 0.75. Full occupancy binding of Mg2+B and Mg2+C may accompany the transition to a closed active-site conformation characterized by optimal metal coordination interactions
Mn2+
-
activates at low concentration below 0.1 mM, inhibits at higher concentrations
Mn2+
-, Q50L36
activates, 34% of the activity with Mg2+
Mn2+
-
can substitute for Mg2+
Mn2+
Mucuna sp.
-
can partially substitute for Mg2+, 20fold lower activity compared to Mg2+
Mn2+
-
can substitute for Mg2+
Ni2+
-, Q50L36
2% of the activity with Mg2+
Zn2+
-, Q50L36
3% of the activity with Mg2+
Mn2+
Q9AR86
can substitute for Mg2+
additional information
-
the enzyme requires low levels of divalent cations
additional information
-, Q50L36
the enzyme requires divalent cations, no activity with Cu2+ and Ca2+
additional information
-
the enzyme is strictly dependent on divalent cations, no activity with Zn2+ and Ca2+
additional information
-
no effect by Ca2+
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
1,10-phenanthroline
-
weak, 20% inhibition at 10 mM
Ca2+
-
inhibitory at higher concentrations
Ca2+
Mucuna sp.
-
stimulates at up to 2 mM, inhibits at 2-30 mM
Co2+
-
inhibits at 1 mM
diethyldicarbonate
-
34-59% inhibition at 1.1 mM, dimethylally diphosphate and Mg2+ protect the soluble enzyme, but not the solubilized thylakoid membrane isozyme
dimethylallyl diphosphate
-
substrate inhibition above 10 mM
diphosphate
-
69-100% inhibition
EDTA
-
40% inhibition at 1 mM, 70% inhibition at 10 mM
Fe2+
-
inhibits at 1 mM
-
Mg2+
-
activates at low concentration below 0.1 mM, inhibits at higher concentrations
NEM
-
complete inactivation at 1.1 mM, dimethylally diphosphate and Mg2+ protect the isozyme partially
Phenylglyoxal
-
50 mM, complete inactivation, dimethylally diphosphate and Mg2+ protect the isozyme partially
Zn2+
-
inhibits at 1 mM
Mn2+
-
activates at low concentration below 0.1 mM, inhibits at higher concentrations
additional information
-
no inhibition by EGTA
-
additional information
-, Q50L36
enzyme expression is highly reduced in the dark
-
additional information
-
enzyme expression and protein levels are highly reduced under elevated O3 but not under elevated CO2 in field-grown aspen trees
-
additional information
-
no inhibition by phosphate
-
additional information
-
no inhibition by PMSF
-
additional information
-
ISPS activity is inhibited by mild drought
-
additional information
-
When photosynthesis is completely inhibited by a 35-day drought stress, the isoprene emission of plants grown at 25C and 35C is strongly inhibited but still measurable, averaging 7.5 nmol/qm/sec. After a 3-day re-watering phase, the isoprene emission rate recovers in plants grown at both 25C and 35C.
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
additional information
-, Q50L36
the enzyme is induced by heat stress and continuous light irradiation
-
additional information
-
the enzyme is positively regulated by light
-
additional information
-
enzyme activity is induced by light, positive regulation
-
additional information
Mucuna sp.
-
the enzyme is positively regulated by light
-
additional information
-
light-dependent regulation of the thylakoid membrane-bound enzyme, overview
-
additional information
-
enzyme activity is induced by light, positive regulation
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.0038
-
dimethylallyl diphosphate
-
Km of 3.8 miromol/qm are estimated from the Lineweaver-Burks plot
0.26
-
dimethylallyl diphosphate
-
using an appropriate conversion factor between area-and volume-based units
0.32
-
dimethylallyl diphosphate
-
-
1.2
-
dimethylallyl diphosphate
-
pH 7.8, 40C, recombinant C-terminally His-tagged enzyme
2.45
-
dimethylallyl diphosphate
-
pH 7.8, 40C, native enzyme
3.1
-
dimethylallyl diphosphate
-
pH 7.8, 40C, recombinant N-terminally His-tagged enzyme
3.68
-
dimethylallyl diphosphate
-
pH 7.8, 40C, recombinant untagged enzyme
8
-
dimethylallyl diphosphate
-
-
8
-
dimethylallyl diphosphate
-
pH 7.8
additional information
-
additional information
-
soluble and membrane-bound isozymes
-
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
1.7
-
dimethylallyl diphosphate
-
-
1.9
-
dimethylallyl diphosphate
-
-
additional information
-
additional information
Q7XAS7
turnover values ranging from 3.7 to 5.1 mmol isoprene mol-1 ISPS under darkness, long-day conditions, i.e. 16 h light, 8 h dark, and continuous light conditions
-
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.000006
-
-
PcISPS activity detected from 2-week-old plant material, Arabidopsis thaliana line 5
0.000012
-
-
PcISPS activity detected from 2-week-old plant material, Arabidopsis thaliana line 10
0.000024
-
-
fraction of transpirable soil water, FTSW, 5%
0.000024
-
Q7XAS7
continuous light condition, time curve over 72h, experiment 2
0.000027
-
Q7XAS7
continuous dark condition, time curve over 72h
0.000036
-
-
fraction of transpirable soil water, FTSW, 10%
0.000036
-
Q7XAS7
continuous light condition, time curve over 72h, experiment 1
0.000042
-
-
PcISPS activity detected from 2-week-old plant material, Arabidopsis thaliana line 3
0.000066
-
-
fraction of transpirable soil water, FTSW, 30%
0.000072
-
-
PcISPS activity detected from 2-week-old plant material, Arabidopsis thaliana line 9
0.000096
-
-
14 days after recovery, DAR
0.00012
-
-
2 days after recovery, DAR
0.000138
-
-
fraction of transpirable soil water, FTSW, 100%
0.00014
-
-
PcISPS activity detected from 2-week-old plant material, Arabidopsis thaliana line 8
0.00039
-
-, Q50L36
leaf cell culture
0.001
-
-
purified thylakoid membrane-bound isozyme
0.011
-
-
purified soluble isozyme
0.012
0.156
Q9AR86
purified recombinant enzyme with or without leader sequence
0.333
-
-
partially purified enzyme
0.521
-
-
purified enzyme
1500
-
Q50L36
cell free exract from leaf transformants
4967
-
Q50L36
native level in Populus alba leaves
additional information
-
-
Quercus robur is a strong emitter of isoprene, measurements of three trees over three days
additional information
-
Mucuna sp.
-
activity and isoprene emission during leaf development, overview
additional information
-
-
activity in subcellular fractions during partial purification, overview
additional information
-
-
A much higher PnISPS activity sustains high rates of isoprene emission in plants grow at 35C before drought stress. Large reductions of PnISPS activity have no relevant effect on isoprene emission in conditions of mild drought stress. The PnISPS activities of leaves grown at 35C do not recover the original rates once drought stress is relieved.; ISPS activity decreases before isoprene emission during drought development, indicating a tighter control of the emission at a transcriptional or post-transcriptional level under moderate drought stress, at 25C and 35C.; PnISPS activity is generally related to isoprene emission rates along the drought treatment; Prior to the imposition of drought stress, plants grown at 35C show much higher PnISPS activities than plants grown at 25C. Drought stress negatively influences PnISPS activity, especially in plants grow at 35C. In these plants, PnISPS activity starts to decrease when drought stress is mild and only partially recovered after re-watering. In plants grown at 25C, the inhibition of PnISPS activity occurred more slowly and only became evident when the stress is severe. At 25C, PnISPS activity recovers rapidly and completely upon re-watering.
additional information
-
-
activity of isoprene synthase remains constant during postillumination process; isoprene synthase mainly operates under substrate limitation and short-term light, CO2 and O2 dependencies of isoprene emission result from variation in dimethylallyl diphosphate pool size rather than from modifications in isoprene synthase activity; maximum capacity of isoprene synthase of Vmax of 110 nmol/qm/s are estimated
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
7.3
-
-
first optimum
7.7
-
-
second optimum
7.8
8.5
Mucuna sp.
-
-
7.8
8.5
-
recombinant C-terminally His-tagged enzyme, recombinant untagged enzyme, and native enzyme
8
-
-, Q50L36
recombinant enzyme
8
-
-
assay at
8
-
-
soluble isozyme
8
-
-
isoprene synthase buffer
8
-
-
activity assay
8
-
Q50L36
activity assay
8
-
Q7XAS7
activity assay
9
-
-
recombinant N-terminally His-tagged enzyme
10
-
-
thylakoid membrane-bound isozyme
pH RANGE
pH RANGE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
5.4
11.2
Mucuna sp.
-
-
6.3
9.2
-
sharp decrease in activity below pH 6.3
6.5
9.5
-, Q50L36
activity range
7.7
8.2
-
broad pH-optimum
additional information
-
-
pH profile
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
28
-
-
assay at
30
-
Mucuna sp.
-
assay at
30
-
-
assay at
32
-
-
assay at
35
-
-
assay at
37
-
-
assay at
40
45
-
optimal temperature for isoprene emission in vivo in warm and cooler regions, respectively
40
50
-
recombinant C-terminally His-tagged enzyme
40
-
-, Q50L36
recombinant enzyme
40
-
Q9AR86
assay at
40
-
-
recombinant N-terminally His-tagged enzyme, recombinant untagged enzyme, and native enzyme
40
-
Q50L36
activity assay, volatile compounds of the reaction are trapped with Solid-Phase Micro Extraction fiber, which is directly injected to a gas-liqiud chromatograph
TEMPERATURE RANGE
TEMPERATURE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
15
50
-
exponential increase of activity from 15C to 40C, optimum activity at 50C, inactivation at 60C
25
50
-, Q50L36
about half-maximal activity at 25C and 50C, temperature profile
26
45
-
no activity in vivo below 20C and above 45C, temperature dependence of activity, it is not closely related to electron flux or CO2 assimilation arte, overview
40
55
-
recombinant N-terminally His-tagged enzyme, recombinant untagged enzyme, and native enzyme
40
60
-
recombinant C-terminally His-tagged enzyme
additional information
-
-
the in vivo rate constant of IspS obeys the Arrhenius law, with an activation energy of 42.8 kJ per mol
pI VALUE
pI VALUE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
4.7
-
-
isoelectric focusing
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
-, Q50L36
from leaves
Manually annotated by BRENDA team
Mucuna sp.
-
activity during leaf development, highest activity an isoprene emission in about 14-days-old leaves, overview
Manually annotated by BRENDA team
-
of transgenic Arabidopsis thaliana
Manually annotated by BRENDA team
A9Q7C9
use for DNA extraction
Manually annotated by BRENDA team
-
from one year old seedlings of hybrid aspen clone 200 which are grown under photosynthetic photon flux density of 0.5 mmol qm/s with 14 light period. Air temperature is kept at 25C during the day and 20C during the night, relative air humidity is 60%. Plants are watered daily with distilled water and once per weak with a combined nutrient solution containing macro- and microelements
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
soluble and membrane-bound isozymes
Manually annotated by BRENDA team
Q9AR86
the enzyme contains a plastidial leader sequence
Manually annotated by BRENDA team
-
the enzyme is localized in the stroma and is also attached to the stromal side of the thylkaoid membrane
Manually annotated by BRENDA team
D8UY76
isoprene synthase requires chloroplastic localization for catalytic activity
Manually annotated by BRENDA team
-, Q50L36
the enzyme contains a plastidial targeting sequence
Manually annotated by BRENDA team
-
soluble enzyme form
-
Manually annotated by BRENDA team
-
tightly membrane-bound enzyme form with a stromal facing, accessible to trypsin treatment
Manually annotated by BRENDA team
-
tightly membrane-bound isozyme with a stromal facing, membrane association via a membrane tail, accessible to trypsin treatment
Manually annotated by BRENDA team
additional information
-
study of subcellular localization, overview
-
Manually annotated by BRENDA team
additional information
-
subcellular localization study, overview
-
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
Populus canescens
Populus canescens
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
52000
-
-
native enzyme, gel filtration
53000
-
-
recombinant untagged enzyme, gel filtration
62000
-
-
recombinant untagged enzyme, native PAGE
90000
100000
-
gel filtration
98000
137000
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
?
Q6EJ97
x * 65000, SDS-PAGE
?
-
x * 68000, SDS-PAGE
dimer
-
1 * 58000 + 1 * 63000, SDS-PAGE
monomer
-
1 * 68000, C-terminally His-tagged enzyme, SDS-PAGE, 1 * 78000, N-terminally His-tagged enzyme, SDS-PAGE
additional information
-, Q50L36
the enzyme contains the aspartate-rich motif DDxxD
additional information
Q9AR86
the enzyme contains the Mg2+-binding DDXXD motif, typical for monoterpene synthases
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
proteolytic modification
-, Q50L36
the enzyme contains a plastidial targeting sequence
proteolytic modification
Q9AR86
the enzyme contains a plastidial leader sequence
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
X-ray crystal structure of recombinant ISPS at 2.7 A resolution, and the structure of its complex with three Mg2+ and theunreactive substrate analogue dimethylallyl-S-thiolodiphosphate determined at 2.8 A resolution. Analysis suggests that the generation of isoprene from substrate dimethylallyl diphosphate occurs via a syn-periplanar elimination mechanism in which the diphosphate-leaving group serves as a general base
-, Q9AR86
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
45
-
stable within
additional information
-
A9Q7C9
thermotolerance of photosynthesis against transient high-temperature episodes can only be observed in lines emitting high levels of isoprene
GENERAL STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
the enzyme activity is very labile and only reproducibly detected when suitable protectants are used in the extraction buffer, especially PMSF is highly stabilizing
-
endogenous isoprene emission of plants plays a protective role against three abiotic stresses (heat, combined heat/light and ozone-induced oxidative stress)
A9Q7C9
isoprene biosynthesis by ISPS is relatively unaffected by drought
-
glycerol stabilizes the enzyme in the early stages of purification, PEG in the late stages
-
OXIDATION STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
isoprene-emitting plants are highly resistant to ozone-induced oxidative damage compared with their non-emitting azygous controls, endogenously produced isoprene provides protection from oxidative damage
A9Q7C9
694648
STORAGE STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
-70C, partially purified enzyme, 40-55% ammonium sulfate fraction, in phosphate buffered saline, pH 7.4, 1mM DTT, stable for at least 1 month
-
-80C, 30-60C ammonium sulfate fraction, resuspended in 50 mM Tris-HCl, pH 8.5, 20 mM MgCl2, 5% glycerol, 2 mM DTT, stable
-
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
native enzyme partially by anion exchange chromatography
-
native enzyme partially by ammonium sulfate fractionation and anion exchange chromatography
Mucuna sp.
-
recombinant enzyme from Escherichia coli
-, Q50L36
native enzyme partially from leaves, recombinant His-tagged enzyme without plastidial targeting sequence from Escherichia coli strain TG1 by nickel affinity chromatography
-
recombinant His-tagged enzyme from Escherichia coli strain TG1
Q9AR86
native enzyme 4000fold from leaves to homogeneity, ammonium sulfate fractionation of cell-free supernatant, dialysis, ion exchange chromatography, ultrafiltration, and gel filtration
-
native enzyme partially from leaves by ammonium sulfate fractionation
-
recombinant His-tagged ISPS from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
-
native enzyme from leaves
-
native enzyme partially from leaves by ammonium sulfate fractionation
-
separation of soluble and membrane-bound isozymes, by ammonium sulfate fractionation, chloroplast preparation, PEG precipitation, hydrophobic interaction and ion exchange chromatography, and gel filtration, the thylakoid membrane isozyme is irreversibly solubilized by pH 10.0 treatment, overview
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
into the pQE50 vector for expression in Escherichia coli, into the binary vector pBinAR for transformation of Agrobacterium tumefaciens and generating transgenic Arabidopsis thaliana plants
-
expressed in Escherichia coli XL1-Blue; expressed in Escherichia coli XL1-Blue
D8UY75, D8UY76
gene ispS, DNA and amino acid sequence determination and analysis, expression in Escherichia coli, expression as GFP-fusion protein in onion peels and tobacco leaves, transformations by particle bombardement
-, Q50L36
the plasmid pGWB2-PaIspS is introduced via Agrobacterium tumefaciens into Arabidopsis plants
Q50L36
transformation of tobacco with an isoprene synthase gene extracted from poplar, obtained plants emitting isoprene at levels comparable to a naturally emitting species, full-length and truncated isoprene synthase cDNAs are amplified
A9Q7C9
expression in Escherichia coli
-
gene ispS, DNA and amino acid sequence determination and analysis, sequence comparisons, expression of His-tagged enzymewith or without leader sequence in Escherichia coli strain TG1
Q9AR86
gene ispS, expression of N-terminally or C-terminally His-tagged enzyme without plastidial targeting sequence in Escherichia coli strain TG1
-
expression analysis under different atmospheric conditions, overview, expression of the His-tagged ISPS in Escherichia coli strain BL21(DE3)
-
into the pET28a vector for production of a polyclonal primary antibody
-
His-tagged version expressed in Escherichia coli, after codon-use optimization expressed in Synechocystis sp. PCC6803
Q6EJ97
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
environmental protection
D8UY76
isoprene emission patterns in transgenic tobacco plants are remarkably similar to naturally emitting plants under a wide variety of conditions. Emissions correlate with photosynthetic rates in developing and mature leaves, and with the amount of isoprene synthase protein in mature leaves. Isoprene synthase protein levels do not change under short-term increase in heat/light, despite an increase in emissions under these conditions. A robust circadian pattern can be observed in emissions from long-day plants. Substrate supply and changes in enzyme kinetics rather than changes in isoprene synthase levels or post-translational regulation of activity seem to be the primary controls on isoprene emission in mature transgenic tobacco leaves
synthesis
-
construction of a synthetic pathway of isoprene in Escherichia coli by introducing an isoprene synthase gene from Populus nigra and overexpression of the native or Bacillus subtilis 1-deoxy-D-xylulose-5-phosphate synthase gene and 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene. Transformants expressing ispS alone accumulate around 94 mg isoprene per liter of broth.Transformants expressing ispS plus the native 1-deoxy-D-xylulose-5-phosphate synthase gene and 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene produce 160 mg isoprene per liter. Transformants expressing ispS plus Bacillus subtilis 1-deoxy-D-xylulose-5-phosphate synthase gene and 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene produce 314 mg isoprene per liter
analysis
-
method for measuring isoprene emission based on postillumination isoprene release after rapid temperature transient, and application to determine the rate constant of isoprene synthase, the pool size of its substrate dimethylallyldiphosphate, and to separate the component processes of the temperature dependence of isoprene emission
environmental protection
-
analysis of in vivo isoprene emission. The in vivo rate constant of IspS obeys the Arrhenius law, with an activation energy of 42.8 kJ per mol. Steady-state isoprene emission has a significantly lower temperature optimum than IspS and higher activation energy. The reversible temperature-dependent decrease in the rate of isoprene emission between 35C and 44C is caused by decreases in dimethylallyl diphosphate concentration, possibly reflecting reduced pools of energetic metabolites generated in photosynthesis, particularly of ATP. Strong control of isoprene temperature responses by the dimethylallyl diphosphate pool implies that transient temperature responses under fluctuating conditions in the field are driven by initial dimethylallyl diphosphate pool size as well as temperature-dependent modifications in dimethylallyl diphosphate pool size during temperature transients
environmental protection
-
regulation of isoprene emission. Upon darkening a leaf, isoprene emission falls nearly to zero but then increases for several min before falling back to nearly zero. Time of appearance of this burst of isoprene is highly temperature dependent, occurring sooner at higher temperatures. During a rapid temperature switch from 30C to 40C, isoprene emission increases transiently with concomitant increase in isoprene synthase activity, while dimethylallyl diphosphate level stays constant during the switch. One h after switching to 40!, the amount of dimethylallyl diphosphate falls but the rate constant for isoprene synthase remains constant, indicating that the high temperature falloff in isoprene emission results from a reduction in the supply of dimethylallyl diphosphate rather than from changes in isoprene synthase activity