IN37_SPIOL
ID IN37_SPIOL Reviewed; 344 AA.
AC P23525;
DT 01-NOV-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1991, sequence version 1.
DT 03-AUG-2022, entry version 78.
DE RecName: Full=2-methyl-6-phytyl-1,4-hydroquinone methyltransferase, chloroplastic;
DE EC=2.1.1.295;
DE AltName: Full=37 kDa inner envelope membrane protein;
DE Short=E37;
DE AltName: Full=MPBQ/MSBQ methyltransferase;
DE Flags: Precursor;
OS Spinacia oleracea (Spinach).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC Caryophyllales; Chenopodiaceae; Chenopodioideae; Anserineae; Spinacia.
OX NCBI_TaxID=3562;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RX PubMed=1997321; DOI=10.1111/j.1432-1033.1991.tb15714.x;
RA Dreses-Werringloer U., Fischer K., Wachter E., Link T.A., Fluegge U.J.;
RT "cDNA sequence and deduced amino acid sequence of the precursor of the 37-
RT kDa inner envelope membrane polypeptide from spinach chloroplasts. Its
RT transit peptide contains an amphiphilic alpha-helix as the only detectable
RT structural element.";
RL Eur. J. Biochem. 195:361-368(1991).
RN [2]
RP PROTEIN SEQUENCE OF 120-141 AND 236-240, AND SUBCELLULAR LOCATION.
RX PubMed=1879527; DOI=10.1016/0014-5793(91)80042-2;
RA Block M.A., Joyard J., Douce R.;
RT "Purification and characterization of E37, a major chloroplast envelope
RT protein.";
RL FEBS Lett. 287:167-170(1991).
CC -!- FUNCTION: Involved in a key methylation step in both tocopherols
CC (vitamin E) and plastoquinone synthesis. Catalyzes the conversion of 2-
CC methyl-6-phytyl-1,4-hydroquinone (MPBQ) to 2,3-dimethyl-6-phytyl-1,4-
CC hydroquinone (DMPQ, a substrate for tocopherol cyclase), and 2-methyl-
CC 6-solanyl-1,4-benzoquinone (MSBQ) to plastoquinone (By similarity).
CC {ECO:0000250}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2-methyl-6-phytyl-1,4-benzene-1,4-diol + S-adenosyl-L-
CC methionine = 2,3-dimethyl-6-phytylbenzene-1,4-diol + H(+) + S-
CC adenosyl-L-homocysteine; Xref=Rhea:RHEA:37979, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:75920,
CC ChEBI:CHEBI:75921; EC=2.1.1.295;
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2-methyl-6-all-trans-nonaprenylbenzene-1,4-diol + S-adenosyl-
CC L-methionine = H(+) + plastoquinol-9 + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:37999, ChEBI:CHEBI:15378, ChEBI:CHEBI:28026,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:75402;
CC EC=2.1.1.295;
CC -!- CATALYTIC ACTIVITY:
CC Reaction=6-geranylgeranyl-2-methylbenzene-1,4-diol + S-adenosyl-L-
CC methionine = 6-geranylgeranyl-2,3-dimethylbenzene-1,4-diol + H(+) +
CC S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:38007, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:75411,
CC ChEBI:CHEBI:75412; EC=2.1.1.295;
CC -!- PATHWAY: Cofactor biosynthesis; tocopherol biosynthesis.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast inner membrane
CC {ECO:0000305|PubMed:1879527}; Single-pass membrane protein
CC {ECO:0000305|PubMed:1879527}.
CC -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC superfamily. MPBQ/MBSQ MT family. {ECO:0000255|PROSITE-
CC ProRule:PRU01069}.
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DR EMBL; X56963; CAA40283.1; -; mRNA.
DR PIR; S14409; S14409.
DR AlphaFoldDB; P23525; -.
DR SMR; P23525; -.
DR PRIDE; P23525; -.
DR UniPathway; UPA00160; -.
DR GO; GO:0009706; C:chloroplast inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0102550; F:2-methyl-6-geranylgeranyl-1,4-benzoquinol methyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0051741; F:2-methyl-6-phytyl-1,4-benzoquinone methyltransferase activity; IEA:InterPro.
DR GO; GO:0051742; F:2-methyl-6-solanyl-1,4-benzoquinone methyltransferase activity; IEA:RHEA.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0010189; P:vitamin E biosynthetic process; IEA:UniProtKB-UniPathway.
DR Gene3D; 3.40.50.150; -; 1.
DR InterPro; IPR013216; Methyltransf_11.
DR InterPro; IPR044649; MPBQ/MSBQ_MT.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR InterPro; IPR031164; SAM_MPBQ_MSBQ_MT.
DR PANTHER; PTHR44516; PTHR44516; 1.
DR Pfam; PF08241; Methyltransf_11; 1.
DR SUPFAM; SSF53335; SSF53335; 1.
DR PROSITE; PS51734; SAM_MPBQ_MSBQ_MT; 1.
PE 1: Evidence at protein level;
KW Chloroplast; Direct protein sequencing; Membrane; Methyltransferase;
KW Plastid; Plastid inner membrane; S-adenosyl-L-methionine; Transferase;
KW Transit peptide; Transmembrane; Transmembrane helix.
FT TRANSIT 1..62
FT /note="Chloroplast"
FT CHAIN 63..344
FT /note="2-methyl-6-phytyl-1,4-hydroquinone
FT methyltransferase, chloroplastic"
FT /id="PRO_0000021513"
FT TOPO_DOM 63..313
FT /note="Chloroplast intermembrane"
FT /evidence="ECO:0000255"
FT TRANSMEM 314..334
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 335..344
FT /note="Stromal"
FT /evidence="ECO:0000255"
FT REGION 121..130
FT /note="SAM motif I"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01069"
FT REGION 166..179
FT /note="SAM motif II"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01069"
FT REGION 207..220
FT /note="SAM motif III"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01069"
SQ SEQUENCE 344 AA; 38976 MW; 555E53242B297D7C CRC64;
MACSMLNGVD KLALISGKTP NRLRFSGSDF TGSYKLPRLN LPPNSRNLRA KTLTTVTKCT
LSASERPASQ PRFIQNKQEA FWFYRFLSIV YDNIINPGHW TEDMRDVALE PADLNNRNML
VVDVGGGTGF TTLGIIKHVD PKNVTILDQS PHQLAKAKAK KPLKECRIIE GDAEDLPFPT
DYADRYVSAG SIEYWPDPQR GIREAYRVLK LGGKACLIGP VYPTFWLSRF FADVWMLFPK
EEEYIEWFQK AGFKDVQLKR IGPKWYRGVR RHGLIMGCSV TGVKPASGDS PLQLGPKVED
VQKPVHPLVF LYRFLLGALA STYYVLVPIY MWIKDKIFPK GMPL
