Information on EC 1.8.99.B2 - tetrathionate reductase

for references in articles please use BRENDA:EC1.8.99.B2
Word Map on EC 1.8.99.B2
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Select one or more organisms in this record:

The enzyme appears in viruses and cellular organisms

EC NUMBER
COMMENTARY hide
1.8.99.B2
preliminary BRENDA-supplied EC number
RECOMMENDED NAME
GeneOntology No.
tetrathionate reductase
-
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
tetrathionate + a reduced electron acceptor = 2 thiosulfate + an oxidized electron acceptor
show the reaction diagram
-
-
-
-
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
physiological function
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
2 thiosulfate + ferricyanide
tetrathionate + ferrocyanide
show the reaction diagram
2 thiosulfate + ubiquinone
tetrathionate + ubiquinol
show the reaction diagram
tetrathionate + a reduced electron acceptor
2 thiosulfate + an oxidized electron acceptor
show the reaction diagram
thiosulfate + oxidized acceptor
tetrathionate + reduced acceptor
show the reaction diagram
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
2 thiosulfate + ubiquinone
tetrathionate + ubiquinol
show the reaction diagram
tetrathionate + a reduced electron acceptor
2 thiosulfate + an oxidized electron acceptor
show the reaction diagram
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
ferricyanide
heme
A8FLS7
sequence shows two Cys-X2-Cys-His heme c-binding motifs, bifunctional tetrathionate reductase/thiosulphate dehydrogenase
additional information
-
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
MgSO4
-
slightly stimulating, at 200 mM
Na2SO4
150 mM Na-sulfate is required to generate maximum activity, 60% inhibition at 200 mM
sulfite
activates 1.6fold at 2 mM, higher concentration of sulfite ions results in inhibition of the enzyme, and almost complete inhibition at 10 mM sulfite
additional information
-
no stimulation of the enzyme by Na2SO4 at at 100 mM
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2-heptyl-4-hydroxy-quinoline N-oxide
-
2-heptyl-4-hydroxyquinoline N-oxide
N-ethylmaleimide
Na+
-
inhibitory at high concentration above 200 mM; inihibits at high concentrations
Na2SO3
-
70% inhibition at 1 mM
Na2SO4
Sodium sulfate
-
100 mM, presence of 200 mM NaCl, 57% residual activity
sodium sulfite
-
0.1 mM, presence of 200 mM NaCl, 45% residual activity
sulfite
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
cofactors might be required for the sulfate-dependent enzyme activation dissociated from the enzyme complex during purification
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.01
tetrathionate
A8FLS7
pH 5.0, 42C
0.81
thiosulfate
-
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
426
tetrathionate
A8FLS7
pH 5.0, 42C
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
42600
tetrathionate
A8FLS7
pH 5.0, 42C
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.5
pH 2.5, 50C, with ferricyanide
13.8
pH 2.5, 70C, with ferricyanide
45
-
purified native enzyme, pH 4.0, 40C
64
A8FLS7
pH 5.0, 42C
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5
A8FLS7
assay at
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
2.5 - 5.5
-
activity range, profile overview
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
42
A8FLS7
assay at
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
enzyme activity measured using ferricyanide as the electron acceptor is detected in cell extracts of Astrain ATCC 23270 grown on tetrathionate or sulfur, but no activity is detected in ferrous iron-grown cells
Manually annotated by BRENDA team
additional information
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
27000
-
gel filtration
27900
-
1 * 27900, SDS-PAGE
36247
A8FLS7
x * 36247, calculated from sequence
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
homodimer
monomer
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
71fold enrichment with a recovery of 4.3% of the total activity
-
native enzyme 71.4fold from the membrane fraction of strain SH by solubilization with n-dodecyl-beta-D-maltopyranoside, ultracentrifugation, anion exchange chromatography, dialysis, ultrafiltration, and gel filtration; native enzyme 71.4fold from the solubilized membrane fraction by ultracentrifugation, anion exchange chromatography, dialysis, and ultrafiltration
-
native periplasmic enzyme from strain ATCC 23270 and recombinant enzyme from Escherichia coli strain BL21(DE3) celll extract by ammonium sulfate fractionation, cation exchange chromatography, dialysis, hydrophobic interaction chromatography, ultrafilatration, and gel filtration
using chromatography on Phenyl-Sepharose column, CM-cellulose column and hydroxylapatite column
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
recombinant enzyme expression in Escherichia coli strain BL21(DE3), subcloning in Escherichia coli strain DH5alpha
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information