KEGG   ENZYME: 1.14.19.30
Entry
EC 1.14.19.30               Enzyme                                 
Name
acyl-lipid (8-3)-desaturase;
acyl-lipid 5-desaturase;
Delta5-fatty-acid desaturase;
DES5 (gene name);
D5des (gene name);
FADS1
Class
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With oxidation of a pair of donors resulting in the reduction of O2 to two molecules of water
Sysname
Delta8 acyl-lipid,ferrocytochrome b5:oxygen oxidoreductase (5,6 cis-dehydrogenating)
Reaction(IUBMB)
(1) an (8Z,11Z,14Z)-icosa-8,11,14-trienoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z)-icosatetra-5,8,11,14-tetraenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O;
(2) an (8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = a (5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O
Substrate
(8Z,11Z,14Z)-icosa-8,11,14-trienoyl-[glycerolipid];
ferrocytochrome b5 [CPD:C00999];
O2 [CPD:C00007];
H+ [CPD:C00080];
(8Z,11Z,14Z,17Z)-icosa-8,11,14,17-tetraenoyl-[glycerolipid]
Product
(5Z,8Z,11Z,14Z)-icosatetra-5,8,11,14-tetraenoyl-[glycerolipid];
ferricytochrome b5 [CPD:C00996];
H2O [CPD:C00001];
(5Z,8Z,11Z,14Z,17Z)-icosa-5,8,11,14,17-pentaenoyl-[glycerolipid]
Comment
The enzyme, which has been characterized from multiple organisms including the moss Physcomitrella patens, the marine microalga Rebecca salina, and the filamentous fungus Mortierella alpina, introduces a cis double bond at the 5-position in 20-carbon polyunsaturated fatty acids incorporated in a glycerolipid that contain a Delta8 double bond. The enzyme contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase, and does not require an external cytochrome.
History
EC 1.14.19.30 created 2015
Orthology
K21735  acyl-lipid (8-3)-desaturase
Genes
SMOSELMODRAFT_235490
PPP112292540
Reference
1  [PMID:9668087]
  Authors
Michaelson LV, Lazarus CM, Griffiths G, Napier JA, Stobart AK
  Title
Isolation of a Delta5-fatty acid desaturase gene from Mortierella alpina.
  Journal
J Biol Chem 273:19055-9 (1998)
DOI:10.1074/jbc.273.30.19055
Reference
2  [PMID:16728405]
  Authors
Kaewsuwan S, Cahoon EB, Perroud PF, Wiwat C, Panvisavas N, Quatrano RS, Cove DJ, Bunyapraphatsara N
  Title
Identification and functional characterization of the moss Physcomitrella patens delta5-desaturase gene involved in arachidonic and eicosapentaenoic acid biosynthesis.
  Journal
J Biol Chem 281:21988-97 (2006)
DOI:10.1074/jbc.M603022200
  Sequence
[ppp:112292540]
Reference
3  [PMID:17291553]
  Authors
Zhou XR, Robert SS, Petrie JR, Frampton DM, Mansour MP, Blackburn SI, Nichols PD, Green AG, Singh SP
  Title
Isolation and characterization of genes from the marine microalga Pavlova salina encoding three front-end desaturases involved in docosahexaenoic acid biosynthesis.
  Journal
Phytochemistry 68:785-96 (2007)
DOI:10.1016/j.phytochem.2006.12.016
Other DBs
ExplorEnz - The Enzyme Database: 1.14.19.30
IUBMB Enzyme Nomenclature: 1.14.19.30
ExPASy - ENZYME nomenclature database: 1.14.19.30
BRENDA, the Enzyme Database: 1.14.19.30

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