Information on EC 1.14.19.4 - DELTA8-fatty-acid desaturase

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The expected taxonomic range for this enzyme is: Eukaryota

EC NUMBER
COMMENTARY
1.14.19.4
-
RECOMMENDED NAME
GeneOntology No.
DELTA8-fatty-acid desaturase
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REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
phytosphinganine + reduced acceptor + O2 = DELTA8-phytosphingenine + acceptor + 2 H2O
show the reaction diagram
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-
-
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REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
oxidation
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oxidation
-
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reduction
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reduction
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PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
arachidonate biosynthesis IV (8-detaturase)
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icosapentaenoate biosynthesis V (Delta;8 desaturase)
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SYSTEMATIC NAME
IUBMB Comments
phytosphinganine,hydrogen donor:oxygen Delta8-oxidoreductase
This enzyme, which has been found mainly in plants, introduces a double bond at Delta8 of C18 and C20 fatty acids [2]. The enzyme from the marine microalga Euglena gracilis requires a double bond to be present at Delta11 and is most active with 20:3 Delta11,14,17 and 20:2 Delta11,14 as substrates, although it can also desaturate 20:1 Delta11 [1]. The Delta8-desaturation pathway represents an alternate pathway for the synthesis of the polyunsaturated fatty acids arachidonate (C20:4 Delta5,8,11,14) and eicosapentaenoate (C20:5 Delta5,8,11,14,17) in organisms lacking a Delta6-desaturase [1]. The enzyme from the sunflower Helianthus annuus and from the herb Borago officinalis comprises a C-terminal desaturase domain and an N-terminal cytochrome-b5 domain [2].
SYNONYMS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Ca-SLDp
-
-
DELTA6-desaturase
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DELTA8 acyl-CoA-dependent desaturase
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DELTA8 desaturase
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DELTA8 desaturase
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DELTA8 sphingobase desaturase
AF001394
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DELTA8 sphingobase desaturase
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Delta8 sphingolipid desaturase
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Delta8 sphingolipid desaturase
AF001394
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Delta8 sphingolipid desaturase
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DELTA8-desaturase
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DELTA8-sphingolipid desaturase
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DELTA8-sphingolipid desaturase
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DELTA8-sphingolipid desaturase
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DELTA8-sphingolipid desaturase
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DELTA8-sphingolipid desaturase
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DELTA8-sphingolipid desaturase
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FADS2
the DELTA6-desaturase FADS2 shows DELTA8-desaturase activity
sphingolipid DELTA8-desaturase
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ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
AF001394
GenBank
Manually annotated by BRENDA team
IFO 1685
SwissProt
Manually annotated by BRENDA team
no activity in Saccharomyces cerevisiae
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-
-
Manually annotated by BRENDA team
gene S581
UniProt
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
(2S,3R)-2-aminoicosane-1,3-diol + reduced acceptor + O2
(E)-(2S,3R)-2-aminoicos-8-ene-1,3-diol + (Z)-(2S,3R)-2-aminoicos-8-ene-1,3-diol + acceptor + H2O
show the reaction diagram
-
-
-
?
(E)-sphing-4-enine + reduced acceptor + O2
(2S,3R,4E,8E)-2-aminooctadeca-4,8-diene-1,3-diol + acceptor + H2O
show the reaction diagram
-
-
-
?
(R)-9-fluorophytosphinganine + reduced acceptor + O2
(Z)-9-fluoro-8-phytosphingenine + acceptor + H2O
show the reaction diagram
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exclusively produces (Z)-9-fluoro-8-phytosphingenine. This result is explained by an initial attack onto the C8-HR and syn-elimination of two vicinal hydrogen atoms via an anti-conformation of the substrate. An initial attack on the C9-F is excluded and generates no product
-
?
(S)-8-fluorophytosphinganine + reduced acceptor + O2
(Z)-8-fluoro-8-phytosphingenine + acceptor + H2O
show the reaction diagram
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product predominantly transformed to (Z)-8-fluoro-8-phytosphingenine along with only trace amounts of the (E)-8-fluoro-8-phytosphingenine (ratio 95:5). This ratio indicates that the fluorinated substrate strongly favors the anti-configuration at the active center of the desaturase
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?
(S)-9-fluorophytosphinganine + reduced acceptor + O2
(E)-9-fluoro-8-phytosphingenine + acceptor + H2O
show the reaction diagram
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produces (E)-9-fluoro-8-phytosphingenine as the sole reaction product. Only the initial attack on the C9-HR in combination with the gauche-conformation of the substrate is productive
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?
11,14,17-eicosatrienoic acid + reduced acceptor + O2
8,11,14,17-eicosatetraenoic acid + acceptor + H2O
show the reaction diagram
-
-
?
11,14,17-eicosatrienoic acid + reduced acceptor + O2
?
show the reaction diagram
20:3n-3, yield 20:4n-3
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-
?
11,14-eicosadienoic acid + reduced acceptor + O2
8,11,14-eicosatrienoic acid + acceptor + H2O
show the reaction diagram
-
-
?
11,14-eicosadienoic acid + reduced acceptor + O2
?
show the reaction diagram
20:2n-6, yield 20:3n-6
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-
?
11-eicosenoic acid + reduced acceptor + O2
8,11-eicosadienoic acid + acceptor + H2O
show the reaction diagram
-
-
?
4-hydroxysphinganine + reduced acceptor + H2O
4-hydroxy-trans-8-sphingenine + acceptor + H2O
show the reaction diagram
-
-
?
phytosphinganine + reduced acceptor + O2
trans-8-sphingenine + cis-8-sphingenine + acceptor + H2O
show the reaction diagram
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-
-
?
phytosphinganine + reduced acceptor + O2
trans-8-sphingenine + cis-8-sphingenine + acceptor + H2O
show the reaction diagram
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-
-
?
phytosphinganine + reduced acceptor + O2
DELTA8-phytosphingenine + acceptor + H2O
show the reaction diagram
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production of two water molecules in the reaction
?
phytosphinganine + reduced acceptor + O2
(8E)-4-hydroxy-8-sphingenine + (8Z)-4-hydroxy-8-sphingenine + acceptor + H2O
show the reaction diagram
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reaction in a in a stereospecific manner by syn elimination of two vicinal hydrogen atoms
production of two water molecules in the reaction
?
sphinganine + reduced acceptor + O2
DELTA8-sphingenine + acceptor + 2 H2O
show the reaction diagram
-
production of two water molecules in the reaction
?
DELTA4-sphingenine + reduced acceptor + O2
DELTA4,8-sphingadienine + acceptor + 2 H2O
show the reaction diagram
-
production of two water molecules in the reaction
?
additional information
?
-
DELTA8 sphingolipid desaturase creates double bonds in long-chain bases, i.e. sphingobases, such as sphinganine, phytosphinganine, or 4-sphingenine to produce E- and Z-isomers of 8-sphingenine, 8-phytosphingenine, or 4,8-sphingadienine, respectively
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-
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additional information
?
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-
(R)-8-fluorophytosphinganine does not yield any desaturation product
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-
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NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
DELTA4-sphingenine + reduced acceptor + O2
DELTA4,8-sphingadienine + acceptor + 2 H2O
show the reaction diagram
A7Y7E1
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production of two water molecules in the reaction
?
phytosphinganine + reduced acceptor + O2
DELTA8-phytosphingenine + acceptor + H2O
show the reaction diagram
A7Y7E1
-
production of two water molecules in the reaction
?
sphinganine + reduced acceptor + O2
DELTA8-sphingenine + acceptor + 2 H2O
show the reaction diagram
A7Y7E1
-
production of two water molecules in the reaction
?
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
cytochrome b5
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the enzyme is composed of a C-terminal desaturase domain and an N-terminal cytochrome b5
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TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
28
-
assay at
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
cloned into pBINI19-35S, transferred to Agrobacterium tumefaciens strain GV3101 and expressed in wild-type Arabidopsis Col 0 or in transgenic line CA1-9 expressing the Isochrysis galbana elongating activity IgASE1; cloned into the yeast expression vector pYES2 and expressed in Saccharomyces serevisiae strain W303-1A
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expression in Saccharomyces cerevisiae
expression in Saccharomyces cerevisiae confers tolerance to aluminium to the cells
AF001394
expression of this open-reading frame in Saccharomyces cerevisiae results in the formation of DELTA-trans/cis-phytosphingenines not present in wild-type cells
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into pBluescript II SK+ and subsequently into pFLAG-Act1
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expression in Saccharomyces cerevisiae
expressed in yeast cells
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expression in Saccharomyces cerevisiae
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functional expression in Saccharomyces cerevisiae, using the constitutive ADH1 promotor of the yeast expression vector pVT-U-102, results in synthesis of acylated (8E)- and (8Z)-4-hydroxy-8-sphingenine via N-acyl-4-hydroxysphinganine from fed deuterium-labeled palmitic acid, primary kinetic isotope effects, overview
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expression in Saccharomyces cerevisiae
expression in Saccharomyces cerevisiae
expression in Saccharomyces cerevisiae
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into the pGEM-T easy vector for sequencing, into the pYES2 vector for expression in Saccharomyces cerevisiae cells
gene S581, DNA and amino acid sequence determination and analysis, expression in Saccharomyces cerevisiae and constitutively in Arabidopsis thaliana, under control of the CaMV35S promoter, confers tolerance to aluminium and gadolinium, Gd3+, but not to lanthanum, La3+, or manganese, Mn2+, to cells and seedlings, respectively, the transgenic expression leads to the accumulation of 8(Z/E)-C18-phytosphingenine and 8(Z/E)-C20-phytopshingenine in yeast and to the accumulation of 8(Z/E)-C18-phytosphingenine in the leaves and roots of Arabidopsis plants, overview
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D208R
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inactive
D210R
-
inactive
F59R
-
the mutant shows markedly decreased activity compared to the wild type enzyme
G28R
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the mutant shows decreased activity compared to the wild type enzyme
G368R
-
inactive
G52R
-
the mutant shows wild type activity
H63R
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inactive
L369A
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the mutant shows markedly decreased activity compared to the wild type enzyme
L71R
-
the mutant shows wild type activity
N203R
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inactive
Q372H
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the mutant shows markedly decreased activity compared to the wild type enzyme
T56R
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the mutant shows decreased activity compared to the wild type enzyme
W190A
-
the mutant shows markedly decreased activity compared to the wild type enzyme
W345A
-
the mutant shows markedly decreased activity compared to the wild type enzyme
Y31A
-
the mutant shows decreased activity compared to the wild type enzyme
A44G
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expressed in yeast, 2-fold higher activity toward 20:2 (n-6), but nor alternation in activity towards 20:3 (n-3) in comparison with the wild-type
additional information
-
chimeras of DELTA6-fatty acid and DELTA8-sphingolipid desaturases