ID   D8FAD_REBSA             Reviewed;         427 AA.
AC   A4KDP1;
DT   11-NOV-2015, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2007, sequence version 1.
DT   03-AUG-2022, entry version 58.
DE   RecName: Full=Acyl-lipid 8-desaturase {ECO:0000305};
DE            EC=1.14.19.- {ECO:0000305|PubMed:17291553};
DE   AltName: Full=Delta-8 desaturase {ECO:0000303|PubMed:17291553};
GN   Name=D8Des {ECO:0000312|EMBL:ABL96296.1};
OS   Rebecca salina (Marine microalga) (Pavlova salina).
OC   Eukaryota; Haptista; Haptophyta; Pavlovales; Pavlovaceae; Rebecca.
OX   NCBI_TaxID=561169;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=CS-49 {ECO:0000312|EMBL:ABL96296.1};
RX   PubMed=17291553; DOI=10.1016/j.phytochem.2006.12.016;
RA   Zhou X.R., Robert S.S., Petrie J.R., Frampton D.M., Mansour M.P.,
RA   Blackburn S.I., Nichols P.D., Green A.G., Singh S.P.;
RT   "Isolation and characterization of genes from the marine microalga Pavlova
RT   salina encoding three front-end desaturases involved in docosahexaenoic
RT   acid biosynthesis.";
RL   Phytochemistry 68:785-796(2007).
CC   -!- FUNCTION: Fatty acid desaturase that introduces a cis double bond at
CC       the 8-position in 20-carbon polyunsaturated fatty acids incorporated in
CC       a glycerolipid that contain a Delta(8) double bond to yield
CC       (20:4(8,11,14,17)). {ECO:0000269|PubMed:17291553}.
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}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; DQ995518; ABL96296.1; -; mRNA.
DR   AlphaFoldDB; A4KDP1; -.
DR   SMR; A4KDP1; -.
DR   PRIDE; A4KDP1; -.
DR   KEGG; ag:ABL96296; -.
DR   BioCyc; MetaCyc:MON-19040; -.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
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; 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   SUPFAM; SSF55856; SSF55856; 1.
DR   PROSITE; PS50255; CYTOCHROME_B5_2; 1.
PE   2: Evidence at transcript 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..427
FT                   /note="Acyl-lipid 8-desaturase"
FT                   /id="PRO_0000434762"
FT   TRANSMEM        189..209
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        261..281
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        286..306
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          36..84
FT                   /note="Cytochrome b5 heme-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT   REGION          1..24
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           178..182
FT                   /note="Histidine box-1"
FT                   /evidence="ECO:0000250|UniProtKB:A0PJ29"
FT   MOTIF           213..218
FT                   /note="Histidine box-2"
FT                   /evidence="ECO:0000250|UniProtKB:A0PJ29"
FT   MOTIF           373..377
FT                   /note="Histidine box-3"
FT                   /evidence="ECO:0000250|UniProtKB:A0PJ29"
FT   BINDING         52
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         75
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   427 AA;  47982 MW;  3306022F8530C300 CRC64;
     MGRGGDSSGQ AHPAAELAVP SDRAEVSNAD SKALHIVLYG KRVDVTKFQR THPGGSKVFR
     IFQDRDATEQ FESYHSKRAI KMMEGMLKKS EDAPADTPLP SQSPMGKDFK AMIERHVAAG
     YYDPCPLDEL FKLSLVLLPT FAGMYMLKAG VGSPLCGALM VSFGWYLDGW LAHDYLHHSV
     FKGSVARTVG WNNAAGYFLG FVQGYAVEWW RARHNTHHVC TNEDGSDPDI KTAPLLIYVR
     NKPSIAKRLN AFQRYQQYYY VPVMAILDLY WRLESIAYVA MRLPKMLPQA LALVAHYAIV
     AWVFAGNYHL LPLVTVLRGF GTGITVFATH YGEDILDADQ VRHMTLVEQT ALTSRNISGG
     WLVNVLTGFI SLQTEHHLFP MMPTGNLMTI QPEVRAFFKK HGLEYREGNL IECVRQNIRA
     LAFEHLL