SQLE_PHATC
ID SQLE_PHATC Reviewed; 348 AA.
AC B7FXW1;
DT 10-APR-2019, integrated into UniProtKB/Swiss-Prot.
DT 10-FEB-2009, sequence version 1.
DT 25-MAY-2022, entry version 55.
DE RecName: Full=Alternative squalene epoxidase {ECO:0000303|PubMed:30478288};
DE Short=AltSQE {ECO:0000303|PubMed:30478288};
DE EC=1.14.19.- {ECO:0000269|PubMed:30478288};
DE AltName: Full=Alternative squalene monooxygenase;
GN ORFNames=PHATRDRAFT_45494;
OS Phaeodactylum tricornutum (strain CCAP 1055/1).
OC Eukaryota; Sar; Stramenopiles; Ochrophyta; Bacillariophyta;
OC Bacillariophyceae; Bacillariophycidae; Naviculales; Phaeodactylaceae;
OC Phaeodactylum.
OX NCBI_TaxID=556484;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, SUBCELLULAR
RP LOCATION, MUTAGENESIS OF HIS-211; HIS-215; HIS-226; HIS-229; HIS-230;
RP HIS-286; HIS-308; HIS-311 AND HIS-312, PATHWAY, COFACTOR, ACTIVITY
RP REGULATION, INTERACTION WITH PHATRDRAFT_30770, AND DOMAIN.
RC STRAIN=CCAP 1055/1;
RX PubMed=30478288; DOI=10.1038/s41564-018-0305-5;
RA Pollier J., Vancaester E., Kuzhiumparambil U., Vickers C.E., Vandepoele K.,
RA Goossens A., Fabris M.;
RT "A widespread alternative squalene epoxidase participates in eukaryote
RT steroid biosynthesis.";
RL Nat. Microbiol. 4:226-233(2019).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCAP 1055/1;
RX PubMed=18923393; DOI=10.1038/nature07410;
RA Bowler C., Allen A.E., Badger J.H., Grimwood J., Jabbari K., Kuo A.,
RA Maheswari U., Martens C., Maumus F., Otillar R.P., Rayko E., Salamov A.,
RA Vandepoele K., Beszteri B., Gruber A., Heijde M., Katinka M., Mock T.,
RA Valentin K., Verret F., Berges J.A., Brownlee C., Cadoret J.P.,
RA Chiovitti A., Choi C.J., Coesel S., De Martino A., Detter J.C., Durkin C.,
RA Falciatore A., Fournet J., Haruta M., Huysman M.J., Jenkins B.D.,
RA Jiroutova K., Jorgensen R.E., Joubert Y., Kaplan A., Kroger N., Kroth P.G.,
RA La Roche J., Lindquist E., Lommer M., Martin-Jezequel V., Lopez P.J.,
RA Lucas S., Mangogna M., McGinnis K., Medlin L.K., Montsant A.,
RA Oudot-Le Secq M.P., Napoli C., Obornik M., Parker M.S., Petit J.L.,
RA Porcel B.M., Poulsen N., Robison M., Rychlewski L., Rynearson T.A.,
RA Schmutz J., Shapiro H., Siaut M., Stanley M., Sussman M.R., Taylor A.R.,
RA Vardi A., von Dassow P., Vyverman W., Willis A., Wyrwicz L.S.,
RA Rokhsar D.S., Weissenbach J., Armbrust E.V., Green B.R., Van de Peer Y.,
RA Grigoriev I.V.;
RT "The Phaeodactylum genome reveals the evolutionary history of diatom
RT genomes.";
RL Nature 456:239-244(2008).
CC -!- FUNCTION: Catalyzes the stereospecific epoxidation of squalene at the
CC terminal double bond to form (S)-2,3-epoxysqualene, the first
CC oxygenation step in sterol biosynthesis. {ECO:0000269|PubMed:30478288}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 + squalene = (S)-2,3-
CC epoxysqualene + 2 Fe(III)-[cytochrome b5] + H2O;
CC Xref=Rhea:RHEA:58916, Rhea:RHEA-COMP:10438, Rhea:RHEA-COMP:10439,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15379,
CC ChEBI:CHEBI:15440, ChEBI:CHEBI:15441, ChEBI:CHEBI:29033,
CC ChEBI:CHEBI:29034; Evidence={ECO:0000269|PubMed:30478288};
CC -!- COFACTOR:
CC Name=Fe cation; Xref=ChEBI:CHEBI:24875;
CC Evidence={ECO:0000305|PubMed:30478288};
CC -!- ACTIVITY REGULATION: The activity of this enzyme is not inhibited by
CC terbinafine, an established inhibitor of the conventional flavoprotein
CC squalene epoxidase. {ECO:0000269|PubMed:30478288}.
CC -!- PATHWAY: Terpene metabolism; lanosterol biosynthesis; lanosterol from
CC farnesyl diphosphate. {ECO:0000305|PubMed:30478288}.
CC -!- SUBUNIT: Interacts with cytochrome b5/PHATRDRAFT_30770.
CC {ECO:0000269|PubMed:30478288}.
CC -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
CC {ECO:0000269|PubMed:30478288}; Multi-pass membrane protein
CC {ECO:0000255}. Note=Detected in the outer envelope of chloroplasts,
CC which is termed the chloroplast endoplasmic reticulum and is continuous
CC with the nuclear envelope. {ECO:0000269|PubMed:30478288}.
CC -!- DOMAIN: The histidine box motifs may contain the active site and/or be
CC involved in metal ion binding. {ECO:0000305|PubMed:30478288}.
CC -!- SIMILARITY: Belongs to the sterol desaturase family. {ECO:0000305}.
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DR EMBL; MH422131; AYI99264.1; -; mRNA.
DR EMBL; CM000610; EEC48820.1; -; Genomic_DNA.
DR RefSeq; XP_002179834.1; XM_002179798.1.
DR AlphaFoldDB; B7FXW1; -.
DR STRING; 556484.B7FXW1; -.
DR EnsemblProtists; Phatr3_J45494.t1; Phatr3_J45494.p1; Phatr3_J45494.
DR GeneID; 7200710; -.
DR KEGG; pti:PHATRDRAFT_45494; -.
DR eggNOG; ENOG502QSQM; Eukaryota.
DR HOGENOM; CLU_798026_0_0_1; -.
DR InParanoid; B7FXW1; -.
DR OMA; YGHLFMW; -.
DR OrthoDB; 1221547at2759; -.
DR Proteomes; UP000000759; Chromosome 7.
DR GO; GO:0005789; C:endoplasmic reticulum membrane; IDA:UniProtKB.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR GO; GO:0004497; F:monooxygenase activity; IMP:UniProtKB.
DR GO; GO:0016126; P:sterol biosynthetic process; IMP:UniProtKB.
DR InterPro; IPR006694; Fatty_acid_hydroxylase.
DR Pfam; PF04116; FA_hydroxylase; 1.
PE 1: Evidence at protein level;
KW Endoplasmic reticulum; Iron; Lipid biosynthesis; Lipid metabolism;
KW Membrane; Oxidoreductase; Reference proteome; Steroid biosynthesis;
KW Transmembrane; Transmembrane helix.
FT CHAIN 1..348
FT /note="Alternative squalene epoxidase"
FT /id="PRO_0000446442"
FT TRANSMEM 55..75
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 105..125
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 153..173
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 243..263
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 277..297
FT /note="Helical"
FT /evidence="ECO:0000255"
FT DOMAIN 197..332
FT /note="Fatty acid hydroxylase"
FT /evidence="ECO:0000255"
FT REGION 1..26
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 211..215
FT /note="Histidine box-1"
FT /evidence="ECO:0000305|PubMed:30478288"
FT MOTIF 226..230
FT /note="Histidine box-2"
FT /evidence="ECO:0000305|PubMed:30478288"
FT MOTIF 308..312
FT /note="Histidine box-3"
FT /evidence="ECO:0000305|PubMed:30478288"
FT COMPBIAS 7..26
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MUTAGEN 211
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 215
FT /note="H->A: Reduces squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 226
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 229
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 230
FT /note="H->A: Reduces squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 286
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 308
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 311
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
FT MUTAGEN 312
FT /note="H->A: Abolishes squalene epoxidase activity."
FT /evidence="ECO:0000269|PubMed:30478288"
SQ SEQUENCE 348 AA; 40150 MW; E42A7395A87AB342 CRC64;
MLVDRVENNE KQQQQMASSS DAMSDSSLSD DEIIEHVVHG KEPKSTYELS WVSNAIAWSG
ALVWPLMLTV PLLLSSMYSP ISYRQVFPES WYVYDTLSNC APKPLGLVLG ILAVAVGQVF
VWIFFYLFKF GYLGTDPRSI QSKGAREYIF REGLLTHIGQ PEGFVLLIGY LAITWMLKLM
PQSYYSFEGT IQYKELFMCL VLQDGIQYTM HVLEHIVSPA FYQMSHKPHH RFTNPRLFDA
FNGSLMDTFC MIIIPLFVTA NLVRHCNVWT YMAFGSSYAC WLTLIHSEYV FPWDGIFRKL
GLGTPADHHV HHKFFKFNYG HLFMWFDQLG GTYRDPSGFA PRVFRENV
