Botryococcene C-methyltransferase (EC 2.1.1.263, TMT-3) is an enzyme with systematic name S-adenosyl-L-methionine:botryococcene C-methyltransferase. This enzyme catalyses the following chemical reaction
2 S-adenosyl-L-methionine + C30 botryococcene
⇌ 2 S-adenosyl-L-homocysteine + 3,20-dimethyl-1,2,21,22-tetradehydro-2,3,20,21-tetrahydrobotryococcene (overall reaction)(1a) S-adenosyl-L-methionine + C30 botryococcene
⇌ S-adenosyl-L-homocysteine + 3-methyl-1,2-didehydro-2,3-dihydrobotryococcene(1b) S-adenosyl-L-methionine + 3-methyl-1,2-didehydro-2,3-dihydrobotryococcene
⇌ S-adenosyl-L-homocysteine + 3,20-dimethyl-1,2,21,22-tetradehydro-2,3,20,21-tetrahydrobotryococcene(2a) S-adenosyl-L-methionine + C30 botryococcene
⇌ S-adenosyl-L-homocysteine + 20-methyl-21,22-didehydro-20,21-dihydrobotryococcene(2b) S-adenosyl-L-methionine + 20-methyl-21,22-didehydro-20,21-dihydrobotryococcene
⇌ S-adenosyl-L-homocysteine + 3,20-dimethyl-1,2,21,22-tetradehydro-2,3,20,21-tetrahydrobotryococcene
This enzyme is isolated from the green alga Botryococcus braunii BOT22.
