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Catalytic Site Atlas

CSA LITERATURE entry for 1afr

E.C. nameacyl-[acyl-carrier-protein] desaturase
SpeciesRicinus communis (Castor bean)
E.C. Number (IntEnz)
CSA Homologues of 1afr1oq4,1oq7,1oq9,1oqb,2j2f,2uw1,
CSA Entries With UniProtID P22337
CSA Entries With EC Number
PDBe Entry 1afr
PDBSum Entry 1afr
MACiE Entry M0136

Literature Report

IntroductionDelta-9 stearoyl-acyl carrier protein desaturase (delta-9 desaturase) is a plastid-localised non-membrane-bound soluble desaturase that introduces the first double bond into saturated fatty acids, resulting in the corresponding mono-unsaturated fatty acids.
MechansimAn electron transport chain carries an electron from ferredoxin to one of the iron centres via several residues. A second electron is then carried to the second iron centre. Several redox reactions take place involving oxygen, water and the iron centres, which result in deprotonation of the substrate and formation of a double bond. For a more detailed mechanism, see MACiE entry M0136.
There are two possible paths for the electron transport chain – the one described here has been chosen because of its analogy to what has been suggested for E. coli ribonucleotide reductase protein R2.

Catalytic Sites for 1afr

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
TrpA6295macie:sideChainTransfers electron from ferredoxin to Asp228.
AspA228261macie:sideChainTransfers electron from Trp62 to His146.
HisA146179macie:sideChainTransfers electron from Asp228 to Fe365 in the first step and to Fe364 in the second step.

Literature References

Lindqvist Y
Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.
EMBO J 1996 15 4081-4092
PubMed: 8861937
Fox BG
Reactions of the diiron enzyme stearoyl-acyl carrier protein desaturase.
Acc Chem Res 2004 37 421-429
PubMed: 15260504
Nordlund P
Structure and function of the Escherichia coli ribonucleotide reductase protein R2.
J Mol Biol 1993 232 123-164
PubMed: 8331655