ID   SC5D_TOBAC              Reviewed;         271 AA.
AC   Q9ZT29;
DT   25-JUL-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1999, sequence version 1.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=Delta(7)-sterol-C5(6)-desaturase;
DE            EC=1.14.19.20;
DE   AltName: Full=Delta(7)-sterol-C5-desaturase;
DE   AltName: Full=Delta-7-C-5 sterol desaturase;
OS   Nicotiana tabacum (Common tobacco).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Nicotianoideae; Nicotianeae;
OC   Nicotiana.
OX   NCBI_TaxID=4097;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Xanthi; TISSUE=Callus;
RX   PubMed=10344195; DOI=10.1023/a:1006113919172;
RA   Husselstein T., Schaller H., Gachotte D., Benveniste P.;
RT   "Delta7-sterol-C5-desaturase: molecular characterization and functional
RT   expression of wild-type and mutant alleles.";
RL   Plant Mol. Biol. 39:891-906(1999).
CC   -!- FUNCTION: Involved in the biosynthesis of sitosterol and campesterol.
CC       {ECO:0000250|UniProtKB:Q39208}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a Delta(7)-sterol + 2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 = a
CC         Delta(5),Delta(7)-sterol + 2 Fe(III)-[cytochrome b5] + 2 H2O;
CC         Xref=Rhea:RHEA:54320, Rhea:RHEA-COMP:10438, Rhea:RHEA-COMP:10439,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15379,
CC         ChEBI:CHEBI:29033, ChEBI:CHEBI:29034, ChEBI:CHEBI:138130,
CC         ChEBI:CHEBI:138131; EC=1.14.19.20;
CC         Evidence={ECO:0000250|UniProtKB:Q39208};
CC   -!- COFACTOR:
CC       Name=Fe cation; Xref=ChEBI:CHEBI:24875; Evidence={ECO:0000250};
CC   -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000305};
CC       Multi-pass membrane protein {ECO:0000305}.
CC   -!- DOMAIN: The histidine box domains may contain the active site and/or be
CC       involved in metal ion binding.
CC   -!- SIMILARITY: Belongs to the sterol desaturase family. {ECO:0000305}.
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DR   EMBL; AF081794; AAD04034.1; -; mRNA.
DR   RefSeq; NP_001311674.1; NM_001324745.1.
DR   AlphaFoldDB; Q9ZT29; -.
DR   STRING; 4097.Q9ZT29; -.
DR   GeneID; 107762070; -.
DR   KEGG; nta:107762070; -.
DR   Proteomes; UP000084051; Unplaced.
DR   GO; GO:0005789; C:endoplasmic reticulum membrane; IBA:GO_Central.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0016020; C:membrane; IBA:GO_Central.
DR   GO; GO:0000248; F:C-5 sterol desaturase activity; IBA:GO_Central.
DR   GO; GO:0050046; F:delta7-sterol 5(6)-desaturase activity; IEA:UniProtKB-EC.
DR   GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR   GO; GO:0016491; F:oxidoreductase activity; IBA:GO_Central.
DR   GO; GO:0016126; P:sterol biosynthetic process; IBA:GO_Central.
DR   InterPro; IPR006694; Fatty_acid_hydroxylase.
DR   Pfam; PF04116; FA_hydroxylase; 1.
PE   2: Evidence at transcript level;
KW   Endoplasmic reticulum; Iron; Lipid biosynthesis; Lipid metabolism;
KW   Membrane; Oxidoreductase; Reference proteome; Steroid biosynthesis;
KW   Steroid metabolism; Sterol biosynthesis; Sterol metabolism; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..271
FT                   /note="Delta(7)-sterol-C5(6)-desaturase"
FT                   /id="PRO_0000117032"
FT   TRANSMEM        44..64
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        120..140
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        190..210
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          130..259
FT                   /note="Fatty acid hydroxylase"
FT                   /evidence="ECO:0000255"
FT   MOTIF           144..148
FT                   /note="Histidine box-1"
FT   MOTIF           158..162
FT                   /note="Histidine box-2"
FT   MOTIF           235..239
FT                   /note="Histidine box-3"
SQ   SEQUENCE   271 AA;  31842 MW;  361520EAAB56D86F CRC64;
     MEDYLKQFVE ETSFYNRLVL GTFMPESWWG PLPHMLQGWL RNYIGGVLLY FISGFLWCFY
     IYHLKRNVYI PKDAIPSNKA MLLQISVAMK AMPWYCALPS LSEYMIENGW TKCFARISDV
     GWLSYVIYAA IYLVIVEFGI YWMHMELHDI KPLYKYLHAT HHIYNKQNTL SPFAGLAFHP
     LDGILQAVPH VVALLLVPMH FSTHIALIFL EALWTANIHD CIHGKVFPVM GAGYHTIHHR
     TYRHNYGHYT IWMDWMFGTL RDPVEEDAKK M