| Accepted Name |
|---|
| tetraether lipid synthase
|
| Alternative Name(s) |
|---|
| GDGT/MA synthase |
| Reaction catalysed |
|---|
- 2 AH2 + 2 archaetidylglycerol + 4 S-adenosyl-L-methionine <=> 4 5'-deoxyadenosine + 2 A + glycerol dibiphytanyl glycerol tetraether glycerophospholipid + 4 H(+) + 4 L-methionine
- AH2 + archaetidylglycerol + 2 S-adenosyl-L-methionine <=> 2 5'-deoxyadenosine + A + 2 H(+) + 2 L-methionine + macrocyclic archaetidylglycerol
|
| Comment(s) |
|---|
- This archaeal enzyme catalyzes a C-C bond formation during the
biosynthesis of tetraether lipids.
- The bond is formed between the termini of two lipid tails from two
glycerophospholipids to generate the macrocycle glycerol dibiphytanyl
glycerol tetraether (GDGT).
- The enzyme does not distinguish whether the two lipids are connected
in antiparallel or parallel geometry, resulting in formation of two
forms of the product, which are known as caldarchaeol and
isocaldarchaeol, respectively.
- The enzyme can also form macrocyclic archaeol phospholipids by
joining the two lipid tails of a single substrate molecule.
- Even though the reaction shown here describes phospholipid
substrates, the enzyme can also act on glycolipids or lipids that
contains mixed types of polar head groups.
- The enzyme is a radical SAM enzyme that contains 3 [4Fe-4S] clusters
and one mononuclear rubredoxin-like iron ion, each found in a
separate domain.
- The enzyme uses the 5'-deoxyadenosyl radical to initiate the
reaction, which involves the formation of an intermediate bond
between the substrate carbon and a sulfur of one of the [4Fe-4S]
clusters.
- Two radicals are needed per C-C bond formed. The source of the
required additional electrons is not known.
|
| Cross-references |
|---|
| BRENDA | 1.21.98.5 |
| EC2PDB | 1.21.98.5 |
| ExplorEnz | 1.21.98.5 |
| PRIAM enzyme-specific profiles | 1.21.98.5 |
| KEGG Ligand Database for Enzyme Nomenclature | 1.21.98.5 |
| IUBMB Enzyme Nomenclature | 1.21.98.5 |
| IntEnz | 1.21.98.5 |
| MEDLINE | Find literature relating to 1.21.98.5 |
| MetaCyc | 1.21.98.5 |
| Rhea expert-curated reactions | 1.21.98.5 |
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