MGDG_SPIOL
ID MGDG_SPIOL Reviewed; 522 AA.
AC Q9SM44;
DT 02-SEP-2008, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 25-MAY-2022, entry version 56.
DE RecName: Full=Monogalactosyldiacylglycerol synthase, chloroplastic;
DE Short=SoMGD1;
DE EC=2.4.1.46;
DE AltName: Full=MGDG synthase type A;
DE Flags: Precursor;
GN Name=MGD A;
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], FUNCTION, ACTIVITY REGULATION, SUBCELLULAR
RP LOCATION, AND SUBUNIT.
RX PubMed=10518794; DOI=10.1046/j.1432-1327.1999.00801.x;
RA Miege C., Marechal E., Shimojima M., Awai K., Block M.A., Ohta H.,
RA Takamiya K., Douce R., Joyard J.;
RT "Biochemical and topological properties of type A MGDG synthase, a spinach
RT chloroplast envelope enzyme catalyzing the synthesis of both prokaryotic
RT and eukaryotic MGDG.";
RL Eur. J. Biochem. 265:990-1001(1999).
RN [2]
RP CHARACTERIZATION.
RX PubMed=8119920; DOI=10.1016/s0021-9258(17)37531-2;
RA Marechal E., Block M.A., Joyard J., Douce R.;
RT "Kinetic properties of monogalactosyldiacylglycerol synthase from spinach
RT chloroplast envelope membranes.";
RL J. Biol. Chem. 269:5788-5798(1994).
RN [3]
RP CHARACTERIZATION, AND ACTIVITY REGULATION.
RX PubMed=7890698; DOI=10.1074/jbc.270.11.5714;
RA Marechal E., Miege C., Block M.A., Douce R., Joyard J.;
RT "The catalytic site of monogalactosyldiacylglycerol synthase from spinach
RT chloroplast envelope membranes. Biochemical analysis of the structure and
RT of the metal content.";
RL J. Biol. Chem. 270:5714-5722(1995).
RN [4]
RP BIOPHYSICOCHEMICAL PROPERTIES, 3D-STRUCTURE MODELING, AND MUTAGENESIS OF
RP TRP-171; GLU-173; TRP-177; HIS-240; HIS-245; CYS-284; CYS-286;
RP 343-GLY--GLY-347; GLU-346; CYS-378; ARG-380; PHE-402; CYS-415; LYS-419;
RP GLU-427; GLU-445 AND ASN-448.
RX PubMed=16009708; DOI=10.1074/jbc.m505622200;
RA Botte C., Jeanneau C., Snajdrova L., Bastien O., Imberty A., Breton C.,
RA Marechal E.;
RT "Molecular modeling and site-directed mutagenesis of plant chloroplast
RT monogalactosyldiacylglycerol synthase reveal critical residues for
RT activity.";
RL J. Biol. Chem. 280:34691-34701(2005).
CC -!- FUNCTION: Involved in the synthesis of the major structural component
CC of photosynthetic membranes. The 1,2-diacylglycerol substrate
CC preference is 18:2/18:2 > 18:0/18:1 > 18:1/18:1 > 18:1/16:0 > 16:0/18:2
CC > 18:3/18:3 > 16:0/18:1 > 16:0/16:0 > 18:0/18:0.
CC {ECO:0000269|PubMed:10518794}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 1,2-diacyl-sn-glycerol + UDP-alpha-D-galactose = a 1,2-
CC diacyl-3-O-(beta-D-galactosyl)-sn-glycerol + H(+) + UDP;
CC Xref=Rhea:RHEA:14945, ChEBI:CHEBI:15378, ChEBI:CHEBI:17615,
CC ChEBI:CHEBI:17815, ChEBI:CHEBI:58223, ChEBI:CHEBI:66914; EC=2.4.1.46;
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000305};
CC -!- ACTIVITY REGULATION: Inhibited by ortho-phenanthroline and UDP
CC (competitive inhibitor relatively to UDP-Gal only) and inactivated by
CC citraconic anhydride, tert-butoxycarbonyl-L-methionine
CC hydrosuccinimidyl ester (SLR) and N-ethylmaleimide (NEM).
CC {ECO:0000269|PubMed:10518794, ECO:0000269|PubMed:7890698}.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=0.65 mM for UDP-Gal {ECO:0000269|PubMed:16009708};
CC -!- SUBUNIT: Homodimer. {ECO:0000305}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast inner membrane
CC {ECO:0000269|PubMed:10518794}.
CC -!- DOMAIN: The C-terminal domain (308-483) is involved in UDP-Gal binding
CC while the N-terminal domains (131-307) is involved in dyacylglycerol
CC binding.
CC -!- SIMILARITY: Belongs to the glycosyltransferase 28 family.
CC {ECO:0000305}.
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DR EMBL; AJ249607; CAB56218.1; -; mRNA.
DR AlphaFoldDB; Q9SM44; -.
DR SMR; Q9SM44; -.
DR CAZy; GT28; Glycosyltransferase Family 28.
DR PRIDE; Q9SM44; -.
DR KEGG; ag:CAB56218; -.
DR OrthoDB; 628561at2759; -.
DR BRENDA; 2.4.1.46; 5812.
DR SABIO-RK; Q9SM44; -.
DR GO; GO:0009706; C:chloroplast inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0046509; F:1,2-diacylglycerol 3-beta-galactosyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0009247; P:glycolipid biosynthetic process; IEA:InterPro.
DR InterPro; IPR009695; Diacylglyc_glucosyltr_N.
DR InterPro; IPR007235; Glyco_trans_28_C.
DR Pfam; PF04101; Glyco_tran_28_C; 1.
DR Pfam; PF06925; MGDG_synth; 1.
PE 1: Evidence at protein level;
KW Chloroplast; Glycosyltransferase; Membrane; Plastid;
KW Plastid inner membrane; Transferase; Transit peptide.
FT TRANSIT 1..98
FT /note="Chloroplast"
FT /evidence="ECO:0000255"
FT CHAIN 99..522
FT /note="Monogalactosyldiacylglycerol synthase,
FT chloroplastic"
FT /id="PRO_5000065674"
FT SITE 422
FT /note="Substrate specificity for galactose"
FT MUTAGEN 171
FT /note="W->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 173
FT /note="E->N: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 177
FT /note="W->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 240
FT /note="H->A: Total loss of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 245
FT /note="H->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 284
FT /note="C->A: No effect."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 286
FT /note="C->A: No effect."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 343..347
FT /note="Missing: Total loss of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 346
FT /note="E->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 378
FT /note="C->A: 25% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 380
FT /note="R->E: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 402
FT /note="F->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 415
FT /note="C->A: No effect."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 419
FT /note="K->A: Total loss of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 427
FT /note="E->A: Total loss of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 445
FT /note="E->A: Total loss of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
FT MUTAGEN 448
FT /note="N->A: 90% reduction of activity."
FT /evidence="ECO:0000269|PubMed:16009708"
SQ SEQUENCE 522 AA; 57511 MW; 02E2B929732551A7 CRC64;
MSHPSTVTSE PSNLLDFVPK LGNFVLNSSL HGNNSNGYSS FSSNSVHFGG LATQNRYKFV
NSLSFSKEGS NLKRILSDFN RVIRLHCDRI PLGFSSIGLN SGESNGVSDN GHGVLEDVRV
PVNAVEPESP KRVLILMSDT GGGHRASAEA IKAAFNEEFG DDYQVFVTDL WSEHTPWPFN
QLPRSYNFLV KHGPLWKMMY YGTSPRVIHQ SNFAATSVFI AREVARGLMK YQPDIIISVH
PLMQHVPLRI LRGRGLLEKI VFTTVVTDLS TCHPTWFHKL VTRCYCPSNE VAKRATKAGL
QPSQIKVYGL PVRPSFVRSV RPKNELRKEL GMDEHLPAVL LMGGGEGMGP IEATARALGN
ALYDANLGEP TGQLLVICGR NKKLAGKLSS IDWKIPVQVK GFVTKIEECM GACDCIITKA
GPGTIAEAMI RGLPIILNDY IAGQEAGNVP YVIENGIGKY LKSPKEIAKT VSQWFGPKAN
ELQIMSQNAL KHARPDAVFK IVHDLDELVR QKIFVRQYSC AA
