KEGG   ENZYME: 2.4.1.241Help
Entry
EC 2.4.1.241                Enzyme                                 

Name
digalactosyldiacylglycerol synthase;
DGD1;
DGD2;
DGDG synthase (ambiguous);
UDP-galactose-dependent DGDG synthase;
UDP-galactose-dependent digalactosyldiacylglycerol synthase;
UDP-galactose:MGDG galactosyltransferase;
UDP-galactose:3-(beta-D-galactosyl)-1,2-diacyl-sn-glycerol 6-alpha-galactosyltransferase
Class
Transferases;
Glycosyltransferases;
Hexosyltransferases
BRITE hierarchy
Sysname
UDP-alpha-D-galactose:1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol 6-alpha-galactosyltransferase
Reaction(IUBMB)
UDP-alpha-D-galactose + 1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol = UDP + 1,2-diacyl-3-O-[alpha-D-galactosyl-(1->6)-beta-D-galactosyl]-sn-glycerol [RN:R04469]
Reaction(KEGG)
Substrate
UDP-alpha-D-galactose [CPD:C00052];
1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol
Product
UDP [CPD:C00015];
1,2-diacyl-3-O-[alpha-D-galactosyl-(1->6)-beta-D-galactosyl]-sn-glycerol
Comment
Requires Mg2+. Diacylglycerol cannot serve as an acceptor molecule for galactosylation as in the reaction catalysed by EC 2.4.1.46, monogalactosyldiacylglyerol synthase. When phosphate is limiting, phospholipids in plant membranes are reduced but these are replaced, at least in part, by the glycolipids digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol [3]. While both DGD1 and DGD2 are increased under phosphate-limiting conditions, DGD2 does not contribute significantly under optimal growth conditions. DGD2 is responsible for the synthesis of DGDG molecular species that are rich in C16 fatty acids at sn-1 of diacylglycerol whereas DGD1 leads to molecular species rich in C18 fatty acids [3]. The enzyme has been localized to the outer side of chloroplast envelope membranes.
History
EC 2.4.1.241 created 2005
Pathway
Glycerolipid metabolism
Metabolic pathways
Orthology
K09480  
digalactosyldiacylglycerol synthase
Genes
ATH: 
AT3G11670(DGD1) AT4G00550(DGD2)
ALY: 
CRB: 
EUS: 
CIT: 
CIC: 
TCC: 
GMX: 
PVU: 
MTR: 
CAM: 
FVE: 
PPER: 
CSV: 
RCU: 
POP: 
POPTR_0006s21970g(POPTRDRAFT_716790) POPTR_0014s07530g(POPTRDRAFT_834731) POPTR_0016s07090g(POPTRDRAFT_835465)
VVI: 
SLY: 
SOT: 
OSA: 
DOSA: 
Os02t0539100-01(Os02g0539100) Os03t0214400-01(Os03g0214400) Os03t0268300-01(Os03g0268300) Os11t0158400-01(Os11g0158400)
OBR: 
BDI: 
SBI: 
SORBI_01g039910(SORBIDRAFT_01g039910) SORBI_04g022040(SORBIDRAFT_04g022040) SORBI_05g003730(SORBIDRAFT_05g003730) SORBI_06g016250(SORBIDRAFT_06g016250)
ZMA: 
SITA: 
ATR: 
s00030p00179690(AMTR_s00030p00179690) s00101p00147880(AMTR_s00101p00147880)
SMO: 
PPP: 
CRE: 
VCN: 
OLU: 
OTA: 
MIS: 
MPP: 
BPG: 
CSL: 
CVR: 
CCP: 
EHX: 
GTT: 
 » show all
Taxonomy
Reference
1  [PMID:11696551]
  Authors
Kelly AA, Dormann P.
  Title
DGD2, an arabidopsis gene encoding a UDP-galactose-dependent digalactosyldiacylglycerol synthase is expressed during growth under phosphate-limiting conditions.
  Journal
J. Biol. Chem. 277 (2002) 1166-73.
  Organism
Arabidopsis thaliana
  Sequence
[ath:AT4G00550]
Reference
2  [PMID:10973486]
  Authors
Hartel H, Dormann P, Benning C.
  Title
DGD1-independent biosynthesis of extraplastidic galactolipids after phosphate deprivation in Arabidopsis.
  Journal
Proc. Natl. Acad. Sci. U. S. A. 97 (2000) 10649-54.
  Organism
Arabidopsis sp.
Reference
3  [PMID:14600212]
  Authors
Kelly AA, Froehlich JE, Dormann P.
  Title
Disruption of the two digalactosyldiacylglycerol synthase genes DGD1 and DGD2 in Arabidopsis reveals the existence of an additional enzyme of galactolipid synthesis.
  Journal
Plant. Cell. 15 (2003) 2694-706.
  Organism
Arabidopsis sp.
  Sequence
Reference
4  [PMID:15590685]
  Authors
Benning C, Ohta H.
  Title
Three enzyme systems for galactoglycerolipid biosynthesis are coordinately regulated in plants.
  Journal
J. Biol. Chem. 280 (2005) 2397-400.
  Organism
Arabidopsis sp.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
69913-00-4

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