SQMT1_BOTBR
ID SQMT1_BOTBR Reviewed; 378 AA.
AC H2E7T5;
DT 06-MAR-2013, integrated into UniProtKB/Swiss-Prot.
DT 21-MAR-2012, sequence version 1.
DT 03-AUG-2022, entry version 28.
DE RecName: Full=Squalene methyltransferase 1;
DE EC=2.1.1.262;
DE AltName: Full=Triterpene methyltransferase 1;
GN Name=TMT-1;
OS Botryococcus braunii (Green alga).
OC Eukaryota; Viridiplantae; Chlorophyta; core chlorophytes; Trebouxiophyceae;
OC Trebouxiophyceae incertae sedis; Elliptochloris clade; Botryococcus.
OX NCBI_TaxID=38881;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND
RP BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=22241476; DOI=10.1074/jbc.m111.316059;
RA Niehaus T.D., Kinison S., Okada S., Yeo Y.S., Bell S.A., Cui P.,
RA Devarenne T.P., Chappell J.;
RT "Functional identification of triterpene methyltransferases from
RT Botryococcus braunii race B.";
RL J. Biol. Chem. 287:8163-8173(2012).
CC -!- FUNCTION: Converts squalene to mono- and dimethyl derivatives, but not
CC to tri- and tetramethylated products. Unable to methylate cycloartenol,
CC zymosterol or lanosterol. Methylates both C-3 and C22 positions, but
CC only C-3 position in monomethylated products. Produces mainly
CC dimethylated squalene. {ECO:0000269|PubMed:22241476}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2 S-adenosyl-L-methionine + squalene = 3,22-dimethyl-
CC 1,2,23,24-tetradehydro-2,3,22,23-tetrahydrosqualene + 2 H(+) + 2 S-
CC adenosyl-L-homocysteine; Xref=Rhea:RHEA:34643, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:15440, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC ChEBI:CHEBI:70861; EC=2.1.1.262;
CC Evidence={ECO:0000269|PubMed:22241476};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=33.1 uM for squalene {ECO:0000269|PubMed:22241476};
CC -!- SUBCELLULAR LOCATION: Microsome membrane {ECO:0000305}; Single-pass
CC membrane protein {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC superfamily. Erg6/SMT family. {ECO:0000255|PROSITE-ProRule:PRU01022}.
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DR EMBL; JN828962; AEY68256.1; -; mRNA.
DR AlphaFoldDB; H2E7T5; -.
DR SMR; H2E7T5; -.
DR KEGG; ag:AEY68256; -.
DR BioCyc; MetaCyc:MON-17324; -.
DR SABIO-RK; H2E7T5; -.
DR GO; GO:0005783; C:endoplasmic reticulum; IEA:UniProtKB-KW.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0008168; F:methyltransferase activity; IEA:UniProtKB-KW.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0006694; P:steroid biosynthetic process; IEA:InterPro.
DR Gene3D; 3.40.50.150; -; 1.
DR InterPro; IPR013216; Methyltransf_11.
DR InterPro; IPR030384; MeTrfase_SMT.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR InterPro; IPR013705; Sterol_MeTrfase_C.
DR Pfam; PF08241; Methyltransf_11; 1.
DR Pfam; PF08498; Sterol_MT_C; 1.
DR SUPFAM; SSF53335; SSF53335; 1.
DR PROSITE; PS51685; SAM_MT_ERG6_SMT; 1.
PE 1: Evidence at protein level;
KW Endoplasmic reticulum; Lipid biosynthesis; Lipid metabolism; Membrane;
KW Methyltransferase; Microsome; S-adenosyl-L-methionine; Transferase;
KW Transmembrane; Transmembrane helix.
FT CHAIN 1..378
FT /note="Squalene methyltransferase 1"
FT /id="PRO_0000421355"
FT TRANSMEM 17..37
FT /note="Helical"
FT /evidence="ECO:0000255"
SQ SEQUENCE 378 AA; 41728 MW; C3A45A75993237C3 CRC64;
MGLDLLSTYA PGIFDSLLTW KGVAGLVVAI TLGYLIISRL PGQKSRPKLL DLKTGGISFE
KVAAVYDDYD KSYGEGDHGE LHVKDKNKVF QLANTFYDFV TDGYEWAWGS SFHFSQRMPG
LSHAASQMLH ESRMASFLRL KPGMKCLDVG CGVGNPGRTV ASCSGAEVTG ITINEYQIKR
AEYHNKRTGL VGYFKPVVGN FCAMPFKDKT FDAAFAMDST CHAPKLEDVY SEVFRVLKPG
GLFATYEWVS TKDYDPNNSR HVKVMNSIIF GNGLPNIRSW KQAEDAGKNV GFKLVTSFDL
ATAPPVGKPW YYVPELMVKY GLLTIQKALV RGACNVGLLP NEGWKVCNMV ADMVPNLVEG
GATNIFTPMH LLIFEKPK
