KEGG   ENZYME: 2.1.1.262Help
Entry
EC 2.1.1.262                Enzyme                                 

Name
squalene methyltransferase;
TMT-1;
TMT-2
Class
Transferases;
Transferring one-carbon groups;
Methyltransferases
BRITE hierarchy
Sysname
S-adenosyl-L-methionine:squalene C-methyltransferase
Reaction(IUBMB)
2 S-adenosyl-L-methionine + squalene = 2 S-adenosyl-L-homocysteine + 3,22-dimethyl-1,2,23,24-tetradehydro-2,3,22,23-tetrahydrosqualene (overall reaction) [RN:R10169];
(1a) S-adenosyl-L-methionine + squalene = S-adenosyl-L-homocysteine + 3-methyl-1,2-didehydro-2,3-dihydrosqualene [RN:R10167];
(1b) S-adenosyl-L-methionine + 3-methyl-1,2-didehydro-2,3-dihydrosqualene = S-adenosyl-L-homocysteine + 3,22-dimethyl-1,2,23,24-tetradehydro-2,3,22,23-tetrahydrosqualene [RN:R10168]
Reaction(KEGG)
Substrate
S-adenosyl-L-methionine [CPD:C00019];
squalene [CPD:C00751];
3-methyl-1,2-didehydro-2,3-dihydrosqualene [CPD:C20411]
Product
S-adenosyl-L-homocysteine [CPD:C00021];
3,22-dimethyl-1,2,23,24-tetradehydro-2,3,22,23-tetrahydrosqualene [CPD:C20412];
3-methyl-1,2-didehydro-2,3-dihydrosqualene [CPD:C20411]
Comment
Two isoforms differing in their specificity were isolated from the green alga Botryococcus braunii BOT22. TMT-1 gave more of the dimethylated form whereas TMT2 gave more of the monomethylated form.
History
EC 2.1.1.262 created 2012
Reference
1  [PMID:22241476]
  Authors
Niehaus TD, Kinison S, Okada S, Yeo YS, Bell SA, Cui P, Devarenne TP, Chappell J
  Title
Functional identification of triterpene methyltransferases from Botryococcus braunii race B.
  Journal
J. Biol. Chem. 287 (2012) 8163-73.
  Organism
Botryococcus braunii
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 

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