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- Name help_outline C30 botryococcene Identifier CHEBI:70786 Charge 0 Formula C30H50 InChIKeyhelp_outline LRCNPQXZCZKGDI-OFGMELEWSA-N SMILEShelp_outline C[C@H](CC\C=C(/C)CCC=C(C)C)\C=C\[C@@](C)(CC\C=C(/C)CCC=C(C)C)C=C 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-adenosyl-L-methionine Identifier CHEBI:59789 Charge 1 Formula C15H23N6O5S InChIKeyhelp_outline MEFKEPWMEQBLKI-AIRLBKTGSA-O SMILEShelp_outline C[S+](CC[C@H]([NH3+])C([O-])=O)C[C@H]1O[C@H]([C@H](O)[C@@H]1O)n1cnc2c(N)ncnc12 2D coordinates Mol file for the small molecule Search links Involved in 842 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 3,20-dimethyl-1,2,21,22-tetradehydro-2,3,20,21-tetrahydrobotryococcene Identifier CHEBI:70865 Charge 0 Formula C32H54 InChIKeyhelp_outline YIERDWVPDSIPLW-HDQHPOANSA-N SMILEShelp_outline C[C@H](CC\C=C(/C)CCC(C)C(C)=C)\C=C\[C@@](C)(CC\C=C(/C)CCC(C)C(C)=C)C=C 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-adenosyl-L-homocysteine Identifier CHEBI:57856 Charge 0 Formula C14H20N6O5S InChIKeyhelp_outline ZJUKTBDSGOFHSH-WFMPWKQPSA-N SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](CSCC[C@H]([NH3+])C([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 768 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:34655 | RHEA:34656 | RHEA:34657 | RHEA:34658 | |
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Publications
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Functional identification of triterpene methyltransferases from Botryococcus braunii race B.
Niehaus T.D., Kinison S., Okada S., Yeo Y.S., Bell S.A., Cui P., Devarenne T.P., Chappell J.
Botryococcus braunii race B is a colony-forming, green algae that accumulates triterpene oils in excess of 30% of its dry weight. The composition of the triterpene oils is dominated by dimethylated to tetramethylated forms of botryococcene and squalene. Although unusual mechanisms for the biosynth ... >> More
Botryococcus braunii race B is a colony-forming, green algae that accumulates triterpene oils in excess of 30% of its dry weight. The composition of the triterpene oils is dominated by dimethylated to tetramethylated forms of botryococcene and squalene. Although unusual mechanisms for the biosynthesis of botryococcene and squalene were recently described, the enzyme(s) responsible for decorating these triterpene scaffolds with methyl substituents were unknown. A transcriptome of B. braunii was screened computationally assuming that the triterpene methyltransferases (TMTs) might resemble the S-adenosyl methionine-dependent enzymes described for methylating the side chain of sterols. Six sterol methyltransferase-like genes were isolated and functionally characterized. Three of these genes when co-expressed in yeast with complementary squalene synthase or botryococcene synthase expression cassettes resulted in the accumulation of mono- and dimethylated forms of both triterpene scaffolds. Surprisingly, TMT-1 and TMT-2 exhibited preference for squalene as the methyl acceptor substrate, whereas TMT-3 showed a striking preference for botryococcene as its methyl acceptor substrate. These in vivo preferences were confirmed with in vitro assays utilizing microsomal preparations from yeast overexpressing the respective genes, which encode for membrane-associated enzymes. Structural examination of the in vivo yeast generated mono- and dimethylated products by NMR identified terminal carbons, C-3 and C-22/C-20, as the atomic acceptor sites for the methyl additions to squalene and botryococcene, respectively. These sites are identical to those previously reported for the triterpenes extracted from the algae. The availability of closely related triterpene methyltransferases exhibiting distinct substrate selectivity and successive catalytic activities provides important tools for investigating the molecular mechanisms responsible for the specificities exhibited by these unique enzymes. << Less
J. Biol. Chem. 287:8163-8173(2012) [PubMed] [EuropePMC]
This publication is cited by 7 other entries.
Comments
Mutli-step reaction: RHEA:34659 and RHEA:34671 Mutli-step reaction: RHEA:34667 and RHEA:34663