D4FAD_EUGGR
ID D4FAD_EUGGR Reviewed; 541 AA.
AC Q6WNG7;
DT 11-NOV-2015, integrated into UniProtKB/Swiss-Prot.
DT 05-JUL-2004, sequence version 1.
DT 03-AUG-2022, entry version 78.
DE RecName: Full=Acyl-lipid (7-3)-desaturase {ECO:0000305};
DE EC=1.14.19.31 {ECO:0000269|PubMed:12911321};
DE AltName: Full=Acyl-lipid 4-desaturase {ECO:0000305};
DE AltName: Full=Delta-4 fatty acid desaturase {ECO:0000303|PubMed:12911321};
GN Name=D4 {ECO:0000303|PubMed:12911321};
OS Euglena gracilis.
OC Eukaryota; Discoba; Euglenozoa; Euglenida; Spirocuta; Euglenophyceae;
OC Euglenales; Euglenaceae; Euglena.
OX NCBI_TaxID=3039;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND CATALYTIC ACTIVITY.
RC STRAIN=Z / UTEX 753;
RX PubMed=12911321; DOI=10.1021/bi034731y;
RA Meyer A., Cirpus P., Ott C., Schlecker R., Zaehringer U., Heinz E.;
RT "Biosynthesis of docosahexaenoic acid in Euglena gracilis: biochemical and
RT molecular evidence for the involvement of a Delta4-fatty acyl group
RT desaturase.";
RL Biochemistry 42:9779-9788(2003).
CC -!- FUNCTION: Fatty acid desaturase that introduces a cis double bond at
CC the 4-position in 22-carbon polyunsaturated fatty acids that contain a
CC Delta(7) double bond, resulting in the production of delta-4
CC desaturated fatty acid docosahexanoic acid (DHA). Also acts on the 16-
CC carbon polyunsaturated fatty acids. {ECO:0000269|PubMed:12911321}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a (7Z,10Z,13Z,16Z,19Z)-docosapentaenoyl-containing
CC glycerolipid + 2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 = a
CC (4Z,7Z,10Z,13Z,16Z,19Z)-docosahexaenoyl-containing glycerolipid + 2
CC Fe(III)-[cytochrome b5] + 2 H2O; Xref=Rhea:RHEA:46252, Rhea:RHEA-
CC COMP:10438, Rhea:RHEA-COMP:10439, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:15379, ChEBI:CHEBI:29033,
CC ChEBI:CHEBI:29034, ChEBI:CHEBI:88266, ChEBI:CHEBI:88267;
CC EC=1.14.19.31; Evidence={ECO:0000269|PubMed:12911321};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a (7Z,10Z,13Z,16Z)-docosatetraenoyl-containing glycerolipid +
CC 2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 = a (4Z,7Z,10Z,13Z,16Z)-
CC docosapentaenoyl-containing glycerolipid + 2 Fe(III)-[cytochrome b5]
CC + 2 H2O; Xref=Rhea:RHEA:46256, Rhea:RHEA-COMP:10438, Rhea:RHEA-
CC COMP:10439, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15379,
CC ChEBI:CHEBI:29033, ChEBI:CHEBI:29034, ChEBI:CHEBI:88264,
CC ChEBI:CHEBI:88265; EC=1.14.19.31;
CC Evidence={ECO:0000269|PubMed:12911321};
CC -!- COFACTOR:
CC Name=Fe(2+); Xref=ChEBI:CHEBI:29033;
CC Evidence={ECO:0000250|UniProtKB:O00767};
CC -!- SUBCELLULAR LOCATION: Membrane {ECO:0000255}; Multi-pass membrane
CC protein {ECO:0000255}.
CC -!- DOMAIN: The cytochrome b5 heme-binding domain acts as the direct
CC electron donor to the active site of the desaturase, and does not
CC require an external cytochrome. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the fatty acid desaturase type 1 family.
CC {ECO:0000305}.
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DR EMBL; AY278558; AAQ19605.1; -; mRNA.
DR AlphaFoldDB; Q6WNG7; -.
DR SwissLipids; SLP:000000557; -.
DR PRIDE; Q6WNG7; -.
DR BRENDA; 1.14.19.31; 2197.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0020037; F:heme binding; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0016717; F:oxidoreductase activity, acting on paired donors, with oxidation of a pair of donors resulting in the reduction of molecular oxygen to two molecules of water; IDA:UniProtKB.
DR GO; GO:0042759; P:long-chain fatty acid biosynthetic process; IDA:UniProtKB.
DR GO; GO:0006636; P:unsaturated fatty acid biosynthetic process; IDA:UniProtKB.
DR Gene3D; 3.10.120.10; -; 1.
DR InterPro; IPR001199; Cyt_B5-like_heme/steroid-bd.
DR InterPro; IPR036400; Cyt_B5-like_heme/steroid_sf.
DR InterPro; IPR018506; Cyt_B5_heme-BS.
DR InterPro; IPR005804; FA_desaturase_dom.
DR InterPro; IPR012171; Fatty_acid_desaturase.
DR PANTHER; PTHR19353; PTHR19353; 1.
DR Pfam; PF00173; Cyt-b5; 1.
DR Pfam; PF00487; FA_desaturase; 1.
DR PIRSF; PIRSF015921; FA_sphinglp_des; 1.
DR SMART; SM01117; Cyt-b5; 1.
DR SUPFAM; SSF55856; SSF55856; 1.
DR PROSITE; PS00191; CYTOCHROME_B5_1; 1.
DR PROSITE; PS50255; CYTOCHROME_B5_2; 1.
PE 1: Evidence at protein level;
KW Electron transport; Fatty acid biosynthesis; Fatty acid metabolism; Heme;
KW Iron; Lipid biosynthesis; Lipid metabolism; Membrane; Metal-binding;
KW Oxidoreductase; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..541
FT /note="Acyl-lipid (7-3)-desaturase"
FT /id="PRO_0000434755"
FT TRANSMEM 186..206
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 209..229
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 314..334
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 356..376
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 383..403
FT /note="Helical"
FT /evidence="ECO:0000255"
FT DOMAIN 75..150
FT /note="Cytochrome b5 heme-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT REGION 15..60
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 229..233
FT /note="Histidine box-1"
FT /evidence="ECO:0000305"
FT MOTIF 264..269
FT /note="Histidine box-2"
FT /evidence="ECO:0000305"
FT MOTIF 476..480
FT /note="Histidine box-3"
FT /evidence="ECO:0000305"
FT BINDING 110
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT BINDING 132
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
SQ SEQUENCE 541 AA; 60183 MW; 0096C52DE05A0AB2 CRC64;
MLVLFGNFYV KQYSQKNGKP ENGATPENGA KPQPCENGTV EKRENDTANV RPTRPAGPPP
ATYYDSLAVS GQGKERLFTT DEVRRHILPT DGWLTCHEGV YDVTDFLAKH PGGGVITLGL
GRDCTILIES YHPAGRPDKV MEKYRIGTLQ DPKTFYAWGE SDFYPELKRR ALARLKEAGQ
ARRGGLGVKA LLVLTLFFVS WYMWVAHKSF LWAAVWGFAG SHVGLSIQHD GNHGAFSRNT
LVNRLAGWGM DLIGASSTVW EYQHVIGHHQ YTNLVSDTLF SLPENDPDVF SSYPLMRMHP
DTAWQPHHRF QHLFAFPLFA LMTISKVLTS DFAVCLSMKK GSIDCSSRLV PLEGQLLFWG
AKLANFLLQI VLPCYLHGTA MGLALFSVAH LVSGEYLAIC FIINHISESC EFMNTSFQTA
ARRTEMLQAA HQAAEAKKVK PTPPPNDWAV TQVQCCVNWR SGGVLANHLS GGLNHQIEHH
LFPSISHANY PTIAPVVKEV CEEYGLPYKN YVTFWDAVCG MVQHLRLMGA PPVPTNGDKK
S
