DB code: S00028

RLCP classification 10.21011.100.10210 : Electron transfer
CATH domain 1.10.620.20 : Ribonucleotide Reductase, subunit A Catalytic domain
E.C. 1.14.19.2
CSA 1afr
M-CSA 1afr
MACiE M0136

CATH domain Related DB codes (homologues)
1.10.620.20 : Ribonucleotide Reductase, subunit A M00151 M00204 M00205

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
P22337 Acyl-[acyl-carrier-protein] desaturase, chloroplastic
EC 1.14.19.2
Delta(9) stearoyl-acyl carrier protein desaturase
Stearoyl-ACP desaturase
XP_002531889.1 (Protein)
XM_002531843.1 (DNA/RNA sequence)
PF03405 (FA_desaturase_2)
[Graphical View]

KEGG enzyme name
acyl-[acyl-carrier-protein] desaturase
stearyl acyl carrier protein desaturase
stearyl-ACP desaturase
acyl-[acyl-carrier-protein], hydrogen-donor:oxygen oxidoreductase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P22337 STAD_RICCO Stearoyl-[acyl-carrier-protein] + reduced acceptor + O(2) = oleoyl-[acyl-carrier-protein] + acceptor + 2 H(2)O. Homodimer. Plastid, chloroplast. Plastid. Note=In green tissue, found in chloroplasts. In non-photosynthetic tissue, found in plastids.

KEGG Pathways
Map code Pathways E.C.
MAP01040 Biosynthesis of unsaturated fatty acids
MAP00061 Fatty acid biosynthesis

Compound table
Cofactors Substrates Products Intermediates
KEGG-id C99999 C00007 C00138 C04088 C00001 C00139 C01203
E.C.
Compound Diiron O2 Reduced ferredoxin Stearoyl-[acyl-carrier protein] H2O Oxidized ferredoxin Oleoyl-[acyl-carrier protein]
Type heavy metal others heavy metal,peptide/protein,sulfide group carbohydrate,lipid,peptide/protein,phosphate group/phosphate ion,sulfide group H2O heavy metal,peptide/protein,sulfide group carbohydrate,lipid,peptide/protein,phosphate group/phosphate ion,sulfide group
ChEBI 15379
26689
27140
15377
PubChem 977
22247451
962
1afrA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1afrB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1afrC Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1afrD Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1afrE Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1afrF Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:FE2-FE2 Unbound Unbound Unbound Unbound Unbound
1oq4A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq4B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq4C Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq4D Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq4E Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq4F Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Analogue:AZI Unbound Unbound Unbound Unbound
1oq7A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq7B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq7C Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq7D Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq7E Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq7F Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound
1oq9A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:_FE-_FE Unbound Unbound Unbound Unbound Unbound
1oqbA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound
1oqbB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound
1oqbC Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound
1oqbD Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound
1oqbE Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound
1oqbF Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:FE2 Unbound Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
literature [1]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1afrA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1afrB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1afrC Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1afrD Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1afrE Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1afrF Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4C Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4D Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4E Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq4F Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7C Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7D Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7E Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq7F Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oq9A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbC Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbD Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbE Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)
1oqbF Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain TRP 62;HIS 146;THR 199;ASP 228 GLU 143;GLU 229(both irons);GLU 196;HIS 232(Iron-1);GLU 105;HIS 146(Iron-2)

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[1]
p.4086-4088
[7]
Fig.5, Fig.6, p.423-425

References
[1]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS)
Medline ID 97015109
PubMed ID 8861937
Journal EMBO J
Year 1996
Volume 15
Pages 4081-92
Authors Lindqvist Y, Huang W, Schneider G, Shanklin J
Title Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.
Related PDB 1afr
Related UniProtKB P22337
[2]
Resource
Comments
Medline ID
PubMed ID 9144157
Journal Proc Natl Acad Sci U S A
Year 1997
Volume 94
Pages 4872-7
Authors Cahoon EB, Lindqvist Y, Schneider G, Shanklin J
Title Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID 9778341
Journal Biochemistry
Year 1998
Volume 37
Pages 14664-71
Authors Broadwater JA, Ai J, Loehr TM, Sanders-Loehr J, Fox BG
Title Peroxodiferric intermediate of stearoyl-acyl carrier protein delta 9 desaturase: oxidase reactivity during single turnover and implications for the mechanism of desaturation.
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID 9812895
Journal Science
Year 1998
Volume 282
Pages 1315-7
Authors Broun P, Shanklin J, Whittle E, Somerville C
Title Catalytic plasticity of fatty acid modification enzymes underlying chemical diversity of plant lipids.
Related PDB
Related UniProtKB
[5]
Resource
Comments
Medline ID
PubMed ID 11294879
Journal J Biol Chem
Year 2001
Volume 276
Pages 21500-5
Authors Whittle E, Shanklin J
Title Engineering delta 9-16:0-acyl carrier protein (ACP) desaturase specificity based on combinatorial saturation mutagenesis and logical redesign of the castor delta 9-18:0-ACP desaturase.
Related PDB
Related UniProtKB
[6]
Resource
Comments X-ray crystallography
Medline ID
PubMed ID 12704186
Journal J Biol Chem
Year 2003
Volume 278
Pages 25072-80
Authors Moche M, Shanklin J, Ghoshal A, Lindqvist Y
Title Azide and acetate complexes plus two iron-depleted crystal structures of the di-iron enzyme delta9 stearoyl-acyl carrier protein desaturase. Implications for oxygen activation and catalytic intermediates.
Related PDB 1oq4 1oq7 1oq9 1oqb
Related UniProtKB
[7]
Resource
Comments
Medline ID
PubMed ID 15260504
Journal Acc Chem Res
Year 2004
Volume 37
Pages 421-9
Authors Fox BG, Lyle KS, Rogge CE
Title Reactions of the diiron enzyme stearoyl-acyl carrier protein desaturase.
Related PDB
Related UniProtKB
[8]
Resource
Comments
Medline ID
PubMed ID 15667224
Journal Biochemistry
Year 2005
Volume 44
Pages 1309-15
Authors Davydov R, Behrouzian B, Smoukov S, Stubbe J, Hoffman BM, Shanklin J
Title Effect of substrate on the diiron(III) site in stearoyl acyl carrier protein delta 9-desaturase as disclosed by cryoreduction electron paramagnetic resonance/electron nuclear double resonance spectroscopy.
Related PDB
Related UniProtKB

Comments
This enzyme was transferred from E.C.1.14.99.6 to E.C. 1.14.19.2.
According to the literature [1], Trp62, His146 & Asp228 might form a route for electron transfer from the enzyme surface to the diiron center. Moreover, Thr199 might be involved in activation of oxygen (see [1]).
According to the literature [7], this enzyme catalyzes three distinct redox reactions. However, this enzyme uses neither NADPH nor ferredoxin reductase directly, although Swissprot data suggested that they are cofactors for this enzyme.
(A) Electron transfer from Ferredoxin to this enzyme active site; Oxidation of ferredoxin (protein).
(B) Electron transfer from acyl-chain to diiron center, producing unsaturated acyl-chain:
(C) O2 reduction to H2O at diiron center: O2 + 4 e(-) + 4 H(+) => 2 H2O
The reaction proceeds as follows:
(A) Electron transfer from Ferredoxin to this enzyme active site; Oxidation of ferredoxin (protein).
(A1) Indirect transfer from [2Fe-2S] of ferredoxin to the diiron of active site of this enzyme through Trp62, Asp228 and His146.

Created Updated
2004-01-26 2018-04-23