KEGG   ENZYME: 1.14.19.19
Entry
EC 1.14.19.19               Enzyme                                 

Name
sphingolipid 10-desaturase;
desA (gene name)
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
a (4E,8E)-sphinga-4,8-dienine ceramide,ferrocytochrome b5:oxygen oxidoreductase (10,11 trans-dehydrogenating)
Reaction(IUBMB)
a (4E,8E)-sphinga-4,8-dienine ceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4E,8E,10E)-sphinga-4,8,10-trienine ceramide + 2 ferricytochrome b5 + 2 H2O [RN:R11006]
Reaction(KEGG)
R11006
Substrate
(4E,8E)-sphinga-4,8-dienine ceramide [CPD:C21022];
ferrocytochrome b5 [CPD:C00999];
O2 [CPD:C00007];
H+ [CPD:C00080]
Product
(4E,8E,10E)-sphinga-4,8,10-trienine ceramide [CPD:C21023];
ferricytochrome b5 [CPD:C00996];
H2O [CPD:C00001]
Comment
The enzyme, characterized from the marine diatom Thalassiosira pseudonana, produces an all-trans product. Similar triunsaturated sphingoid bases are found in some marine invertebrates. The enzyme determines the position of the double bond by its distance from the alcohol end of the sphingoid base, and contains a cytochrome b5 domain that acts as the direct electron donor to the active site of the desaturase.
History
EC 1.14.19.19 created 2015
Orthology
K21733  sphingolipid 10-desaturase
Genes
TPS: THAPSDRAFT_22804
Reference
1  [PMID:23510654]
  Authors
Michaelson LV, Markham JE, Zaeuner S, Matsumoto M, Chen M, Cahoon EB, Napier JA
  Title
Identification of a cytochrome b5-fusion desaturase responsible for the synthesis of triunsaturated sphingolipid long chain bases in the marine diatom Thalassiosira pseudonana.
  Journal
Phytochemistry 90:50-5 (2013)
DOI:10.1016/j.phytochem.2013.02.010
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 1.14.19.19
IUBMB Enzyme Nomenclature: 1.14.19.19
ExPASy - ENZYME nomenclature database: 1.14.19.19
BRENDA, the Enzyme Database: 1.14.19.19
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