Information on EC 5.4.4.5 - 9,12-octadecadienoate 8-hydroperoxide 8R-isomerase

for references in articles please use BRENDA:EC5.4.4.5
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 expected taxonomic range for this enzyme is: Aspergillus

EC NUMBER
COMMENTARY hide
5.4.4.5
-
RECOMMENDED NAME
GeneOntology No.
9,12-octadecadienoate 8-hydroperoxide 8R-isomerase
-
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
(8R,9Z,12Z)-8-hydroperoxyoctadeca-9,12-dienoate = (5S,8R,9Z,12Z)-5,8-dihydroxyoctadeca-9,12-dienoate
show the reaction diagram
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Linoleic acid metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
(8R,9Z,12Z)-8-hydroperoxyoctadeca-9,12-dienoate hydroxymutase [(5S,8R,9Z,12Z)-5,8-dihydroxyoctadeca-9,12-dienoate-forming]
The enzyme contains heme [3]. The bifunctional enzyme from Aspergillus nidulans uses different heme domains to catalyse two separate reactions. Linoleic acid is oxidized within the N-terminal heme peroxidase domain to (8R,9Z,12Z)-8-hydroperoxyoctadeca-9,12-dienoate (cf. EC 1.13.11.60, linoleate 8R-lipoxygenase), which is subsequently isomerized to (5S,8R,9Z,12Z)-5,8-dihydroxyoctadeca-9,12-dienoate within the C-terminal P-450 heme thiolate domain [3].
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
C1KH66
UniProt
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
(8R,9Z,12Z)-8-hydroperoxy-10,12-octadecadienoate
(7S,8S,9Z,12Z)-7,8-dihydroxyoctadeca-9,12-dienoate
show the reaction diagram
C1KH66
-
-
-
?
(8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate
(5S,8R,9Z,12Z)-5,8-dihydroxy-9,12-octadecadienoate
show the reaction diagram
(8R,9Z,12Z)-9-hydroperoxy-10,12-octadecadienoate
(5S,8R,9Z,12Z)-5,8-dihydroxyoctadeca-9,12-dienoate
show the reaction diagram
C1KH66
-
-
-
?
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
(8R,9Z,12Z)-8-hydroperoxy-10,12-octadecadienoate
(7S,8S,9Z,12Z)-7,8-dihydroxyoctadeca-9,12-dienoate
show the reaction diagram
C1KH66
-
-
-
?
(8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate
(5S,8R,9Z,12Z)-5,8-dihydroxy-9,12-octadecadienoate
show the reaction diagram
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
heme
PpoA contains a high spin ferriheme. PpoA uses different heme domains to catalyze two separate reactions. Within the heme peroxidase domain, linoleic acid is oxidized to (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate is isomerized within the P450 heme thiolate domain to (5S,8R,9Z,12Z)-5,8-dihydroxy-9,12-octadecadienoate
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
suicide inactivation, activity falls to zero within a few min although substrates are available in sufficient amounts
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
additional information
C1KH66
kinetic data of truncated enzymes
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
3.2
pH 7.2, 24°C
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
110000
4 * 110000, SDS-PAGE
440000
gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
tetramer
4 * 110000, SDS-PAGE
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expression in Escherichia coli
expression in Escherichia coli and in insect cells
C1KH66
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
C1006S
C1KH66
the hydroperoxide isomerase activity of 5,8-LDS mutant is abolished
Y374F
C1KH66
mutation in the conserved sequence YRWH results in loss of linoleate 8R-lipoxygenase activity, whereas the hydroperoxide isomerase activity is retained
H1004A
mutant enzyme with abolished 8-hydroperoxide isomerase activity, whereas dioxygenase activity is still present
Y374
the mutant enzyme shows no detectable activity when incubated with (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate as a substrate. When incubated with the intermediate product (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoateit it is able to catalyze isomerization to (5S,8R,9Z,12Z)-5,8-dihydroperoxy-9,12-octadecadienoate
additional information
C1KH66
replacements of Tyr and Cys in the conserved YRWH and FXXGPHXCLG sequences abolishes 8R-dioxygenase (8-DOX) and hydroperoxide isomerase activities, respectively. Val328 of 5,8-LDS does not influence the position of oxygenation