ID   FDFT_EREGS              Reviewed;         441 AA.
AC   Q752X9;
DT   31-AUG-2004, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   24-JAN-2024, entry version 116.
DE   RecName: Full=Squalene synthase;
DE            Short=SQS;
DE            Short=SS;
DE            EC=2.5.1.21;
DE   AltName: Full=FPP:FPP farnesyltransferase;
DE   AltName: Full=Farnesyl-diphosphate farnesyltransferase;
GN   Name=ERG9; OrderedLocusNames=AFR444C;
OS   Eremothecium gossypii (strain ATCC 10895 / CBS 109.51 / FGSC 9923 / NRRL
OS   Y-1056) (Yeast) (Ashbya gossypii).
OC   Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes;
OC   Saccharomycetales; Saccharomycetaceae; Eremothecium.
OX   NCBI_TaxID=284811;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 10895 / CBS 109.51 / FGSC 9923 / NRRL Y-1056;
RX   PubMed=15001715; DOI=10.1126/science.1095781;
RA   Dietrich F.S., Voegeli S., Brachat S., Lerch A., Gates K., Steiner S.,
RA   Mohr C., Poehlmann R., Luedi P., Choi S., Wing R.A., Flavier A.,
RA   Gaffney T.D., Philippsen P.;
RT   "The Ashbya gossypii genome as a tool for mapping the ancient Saccharomyces
RT   cerevisiae genome.";
RL   Science 304:304-307(2004).
RN   [2]
RP   GENOME REANNOTATION.
RC   STRAIN=ATCC 10895 / CBS 109.51 / FGSC 9923 / NRRL Y-1056;
RX   PubMed=23749448; DOI=10.1534/g3.112.002881;
RA   Dietrich F.S., Voegeli S., Kuo S., Philippsen P.;
RT   "Genomes of Ashbya fungi isolated from insects reveal four mating-type
RT   loci, numerous translocations, lack of transposons, and distinct gene
RT   duplications.";
RL   G3 (Bethesda) 3:1225-1239(2013).
CC   -!- FUNCTION: Catalyzes the condensation of 2 two farnesyl pyrophosphate
CC       moieties to form squalene. It is the first committed enzyme of the
CC       sterol biosynthesis pathway. Required for the biosynthesis of
CC       ergosterol (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 (2E,6E)-farnesyl diphosphate + H(+) + NADPH = 2 diphosphate
CC         + NADP(+) + squalene; Xref=Rhea:RHEA:32295, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:15440, ChEBI:CHEBI:33019, ChEBI:CHEBI:57783,
CC         ChEBI:CHEBI:58349, ChEBI:CHEBI:175763; EC=2.5.1.21;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 (2E,6E)-farnesyl diphosphate + H(+) + NADH = 2 diphosphate +
CC         NAD(+) + squalene; Xref=Rhea:RHEA:32299, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:15440, ChEBI:CHEBI:33019, ChEBI:CHEBI:57540,
CC         ChEBI:CHEBI:57945, ChEBI:CHEBI:175763; EC=2.5.1.21;
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250};
CC   -!- PATHWAY: Terpene metabolism; lanosterol biosynthesis; lanosterol from
CC       farnesyl diphosphate: step 1/3.
CC   -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000250};
CC       Multi-pass membrane protein {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the phytoene/squalene synthase family.
CC       {ECO:0000305}.
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DR   EMBL; AE016819; AAS53815.1; -; Genomic_DNA.
DR   RefSeq; NP_985991.1; NM_211346.1.
DR   AlphaFoldDB; Q752X9; -.
DR   SMR; Q752X9; -.
DR   STRING; 284811.Q752X9; -.
DR   EnsemblFungi; AAS53815; AAS53815; AGOS_AFR444C.
DR   GeneID; 4622268; -.
DR   KEGG; ago:AGOS_AFR444C; -.
DR   eggNOG; KOG1459; Eukaryota.
DR   HOGENOM; CLU_031981_2_1_1; -.
DR   InParanoid; Q752X9; -.
DR   OMA; GEACQLM; -.
DR   OrthoDB; 5487739at2759; -.
DR   UniPathway; UPA00767; UER00751.
DR   Proteomes; UP000000591; Chromosome VI.
DR   GO; GO:0005789; C:endoplasmic reticulum membrane; IBA:GO_Central.
DR   GO; GO:0004310; F:farnesyl-diphosphate farnesyltransferase activity; IBA:GO_Central.
DR   GO; GO:0051996; F:squalene synthase activity; IBA:GO_Central.
DR   GO; GO:0006696; P:ergosterol biosynthetic process; IBA:GO_Central.
DR   GO; GO:0045338; P:farnesyl diphosphate metabolic process; IBA:GO_Central.
DR   GO; GO:0008299; P:isoprenoid biosynthetic process; IEA:UniProtKB-KW.
DR   CDD; cd00683; Trans_IPPS_HH; 1.
DR   Gene3D; 1.10.600.10; Farnesyl Diphosphate Synthase; 1.
DR   InterPro; IPR008949; Isoprenoid_synthase_dom_sf.
DR   InterPro; IPR002060; Squ/phyt_synthse.
DR   InterPro; IPR006449; Squal_synth-like.
DR   InterPro; IPR019845; Squalene/phytoene_synthase_CS.
DR   InterPro; IPR044844; Trans_IPPS_euk-type.
DR   InterPro; IPR033904; Trans_IPPS_HH.
DR   NCBIfam; TIGR01559; squal_synth; 1.
DR   PANTHER; PTHR11626; FARNESYL-DIPHOSPHATE FARNESYLTRANSFERASE; 1.
DR   PANTHER; PTHR11626:SF2; SQUALENE SYNTHASE; 1.
DR   Pfam; PF00494; SQS_PSY; 1.
DR   SFLD; SFLDS00005; Isoprenoid_Synthase_Type_I; 1.
DR   SFLD; SFLDG01018; Squalene/Phytoene_Synthase_Lik; 1.
DR   SUPFAM; SSF48576; Terpenoid synthases; 1.
DR   PROSITE; PS01044; SQUALEN_PHYTOEN_SYN_1; 1.
DR   PROSITE; PS01045; SQUALEN_PHYTOEN_SYN_2; 1.
PE   3: Inferred from homology;
KW   Endoplasmic reticulum; Isoprene biosynthesis; Lipid biosynthesis;
KW   Lipid metabolism; Magnesium; Membrane; Multifunctional enzyme; NADP;
KW   Reference proteome; Steroid biosynthesis; Steroid metabolism;
KW   Sterol biosynthesis; Sterol metabolism; Transferase; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..441
FT                   /note="Squalene synthase"
FT                   /id="PRO_0000067446"
FT   TRANSMEM        293..313
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        420..440
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   441 AA;  50873 MW;  53807044FB95195B CRC64;
     MGKVVQLFTH PLELKAALKL KFLREPLYPA DDTQGSAELK RCYQLLQRTS RSFAAVIMEL
     HPELRNAVML FYLILRALDT VEDDMTISPK VKVPLLREFD QKLKLDTWSF DGNAKTEKDR
     DVLVEFSTIL AEFHKLKPEY QQVIADITHK MGNGMADYIL DEKFNLSGLE TIQDYDRYCH
     YVAGLVGDGL THLIMLAKFS SPGLYYDSPD LYESMGLFLQ KTNIIRDYAE DLADGRSFWP
     KEIWSHYADD LASFSKPENA TAGVYCINHL VLNALGHVQH VLTYLASLRE QSSFQFCAIP
     QVMAIATLAL VFGNERVLQT SVKIRKGTTC YLILKSRTFQ GCVEIFEHYL RDIRKRLTVA
     DPNYLKLNIE IAKLDKFIEE MYQDKLPVGA KPQETEIYKK VRERSAYDLE VLPREQEEEF
     KFNVLLSILF TVFGALYWYA K
//