Accepted name: 2,3-bis-O-geranylgeranyl-sn-glycerol 1-phosphate reductase [NAD(P)H]
Reaction: 2,3-bis-(O-phytanyl)-sn-glycerol 1-phosphate + 8 NAD(P)+ = 2,3-bis-(O-geranylgeranyl)-sn-glycerol 1-phosphate + 8 NAD(P)H + 8 H+
Glossary: phytanol = (7R,11R,15R)-3,7,11,15-tetramethylhexadecan-1-ol
Other name(s): digeranylgeranylglycerophospholipid reductase; Ta0516m (gene name); DGGGPL reductase; 2,3-digeranylgeranylglycerophospholipid reductase
Systematic name: 2,3-bis-(O-phytany)l-sn-glycerol 1-phosphate:NAD(P)+ oxidoreductase
Comments: A flavoprotein (FAD). The enzyme from the archaeon Thermoplasma acidophilum is involved in the biosynthesis of membrane lipids. In vivo the reaction occurs in the reverse direction with the formation of 2,3-bis-O-phytanyl-sn-glycerol 1-phosphate. cf. EC, 2,3-bis-O-geranylgeranyl-sn-glycero-phospholipid reductase.
1.  Nishimura, Y. and Eguchi, T. Biosynthesis of archaeal membrane lipids: digeranylgeranylglycerophospholipid reductase of the thermoacidophilic archaeon Thermoplasma acidophilum. J. Biochem. 139 (2006) 1073–1081. [PMID: 16788058]
2.  Nishimura, Y. and Eguchi, T. Stereochemistry of reduction in digeranylgeranylglycerophospholipid reductase involved in the biosynthesis of archaeal membrane lipids from Thermoplasma acidophilum. Bioorg. Chem. 35 (2007) 276–283. [PMID: 17275067]
3.  Xu, Q., Eguchi, T., Mathews, I.I., Rife, C.L., Chiu, H.J., Farr, C.L., Feuerhelm, J., Jaroszewski, L., Klock, H.E., Knuth, M.W., Miller, M.D., Weekes, D., Elsliger, M.A., Deacon, A.M., Godzik, A., Lesley, S.A. and Wilson, I.A. Insights into substrate specificity of geranylgeranyl reductases revealed by the structure of digeranylgeranylglycerophospholipid reductase, an essential enzyme in the biosynthesis of archaeal membrane lipids. J. Mol. Biol. 404 (2010) 403–417. [PMID: 20869368]
[EC created 2013]
Transferred entry: 2,3-bis-O-geranylgeranyl-sn-glycerol 1-phosphate reductase (donor). Now classified as EC, 2,3-bis-O-geranylgeranyl-sn-glycero-phospholipid reductase.
[EC created 2013, deleted 2015]
Accepted name: geranylgeranylglycerol-phosphate geranylgeranyltransferase
Reaction: geranylgeranyl diphosphate + 3-(O-geranylgeranyl)-sn-glycerol 1-phosphate = diphosphate + 2,3-bis-(O-geranylgeranyl)-sn-glycerol 1-phosphate
Other name(s): geranylgeranyloxyglycerol phosphate geranylgeranyltransferase; geranylgeranyltransferase II; (S)-2,3-di-O-geranylgeranylglyceryl phosphate synthase; DGGGP synthase; DGGGPS; geranylgeranyl diphosphate:sn-3-O-(geranylgeranyl)glycerol 1-phosphate geranylgeranyltransferase
Systematic name: geranylgeranyl-diphosphate:3-(O-geranylgeranyl)-sn-glycerol 1-phosphate geranylgeranyltransferase
Comments: This enzyme is an integral-membrane protein that carries out the second prenyltransfer reaction involved in the formation of polar membrane lipids in Archaea. Requires a divalent metal cation, such as Mg2+ or Mn2+, for activity [2]. 4-Hydroxybenzoate, 1,4-dihydroxy 2-naphthoate, homogentisate and α-glycerophosphate cannot act as prenyl-acceptor substrates [2]. The other enzymes involved in the biosynthesis of polar lipids in Archaea are EC (sn-glycerol-1-phosphate dehydrogenase), EC (phosphoglycerol geranylgeranyltransferase), which, together with this enzyme, alkylates the hydroxy groups of glycerol 1-phosphate to yield unsaturated archaetidic acid, which is acted upon by EC [CDP-2,3-bis-(O-geranylgeranyl)-sn-glycerol synthase] to form CDP-unsaturated archaeol. The final step in the pathway involves the addition of L-serine, with concomitant removal of CMP, leading to the production of unsaturated archaetidylserine [3]. Belongs in the UbiA prenyltransferase family [2].
1.  Zhang, D.-L., Daniels, L. and Poulter, C.D. Biosynthesis of archaebacterial membranes. Formation of isoprene ethers by a prenyl transfer reaction. J. Am. Chem. Soc. 112 (1990) 1264–1265.
2.  Hemmi, H., Shibuya, K., Takahashi, Y., Nakayama, T. and Nishino, T. (S)-2,3-Di-O-geranylgeranylglyceryl phosphate synthase from the thermoacidophilic archaeon Sulfolobus solfataricus. Molecular cloning and characterization of a membrane-intrinsic prenyltransferase involved in the biosynthesis of archaeal ether-linked membrane lipids. J. Biol. Chem. 279 (2004) 50197–50203. [PMID: 15356000]
3.  Morii, H., Nishihara, M. and Koga, Y. CTP:2,3-di-O-geranylgeranyl-sn-glycero-1-phosphate cytidyltransferase in the methanogenic archaeon Methanothermobacter thermoautotrophicus. J. Biol. Chem. 275 (2000) 36568–36574. [PMID: 10960477]
[EC created 1992, modified 2009]
Accepted name: CDP-2,3-bis-(O-geranylgeranyl)-sn-glycerol synthase
Reaction: CTP + 2,3-bis-(O-geranylgeranyl)-sn-glycerol 1-phosphate = diphosphate + CDP-2,3-bis-(O-geranylgeranyl)-sn-glycerol
Glossary: 2,3-bis-(O-geranylgeranyl)-sn-glycerol 1-phosphate = 2,3-bis-(O-geranylgeranyl)-glycerophosphate ether = unsaturated archaetidic acid
CDP-unsaturated archaeol = CDP-2,3-bis-(O-geranylgeranyl)-sn-glycerol
Other name(s): carS (gene name); CDP-2,3-di-O-geranylgeranyl-sn-glycerol synthase; CTP:2,3-GG-GP ether cytidylyltransferase; CTP:2,3-di-O-geranylgeranyl-sn-glycero-1-phosphate cytidyltransferase; CDP-2,3-bis-O-(geranylgeranyl)-sn-glycerol synthase; CTP:2,3-bis-O-(geranylgeranyl)-sn-glycero-1-phosphate cytidylyltransferase; CDP-unsaturated archaeol synthase; CDP-archaeol synthase (incorrect)
Systematic name: CTP:2,3-bis-(O-geranylgeranyl)-sn-glycerol 1-phosphate cytidylyltransferase
Comments: This enzyme catalyses one of the steps in the biosynthesis of polar lipids in archaea, which are characterized by having an sn-glycerol 1-phosphate backbone rather than an sn-glycerol 3-phosphate backbone as is found in bacteria and eukaryotes [1]. The enzyme requires Mg2+ and K+ for maximal activity [1].
1.  Morii, H., Nishihara, M. and Koga, Y. CTP:2,3-di-O-geranylgeranyl-sn-glycero-1-phosphate cytidyltransferase in the methanogenic archaeon Methanothermobacter thermoautotrophicus. J. Biol. Chem. 275 (2000) 36568–36574. [PMID: 10960477]
2.  Morii, H. and Koga, Y. CDP-2,3-di-O-geranylgeranyl-sn-glycerol:L-serine O-archaetidyltransferase (archaetidylserine synthase) in the methanogenic archaeon Methanothermobacter thermautotrophicus. J. Bacteriol. 185 (2003) 1181–1189. [PMID: 12562787]
3.  Jain, S., Caforio, A., Fodran, P., Lolkema, J.S., Minnaard, A.J. and Driessen, A.J. Identification of CDP-archaeol synthase, a missing link of ether lipid biosynthesis in Archaea. Chem. Biol. 21 (2014) 1392–1401. [PMID: 25219966]
[EC created 2009, modified 2014]