Reaction participants Show >> << Hide
- Name help_outline squalene Identifier CHEBI:15440 (Beilstein: 1728920; CAS: 111-02-4) help_outline Charge 0 Formula C30H50 InChIKeyhelp_outline YYGNTYWPHWGJRM-AAJYLUCBSA-N SMILEShelp_outline CC(C)=CCC\C(C)=C\CC\C(C)=C\CC\C=C(/C)CC\C=C(/C)CCC=C(C)C 2D coordinates Mol file for the small molecule Search links Involved in 13 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
Fe(II)-[cytochrome b5]
Identifier
RHEA-COMP:10438
Reactive part
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- Name help_outline Fe2+ Identifier CHEBI:29033 (CAS: 15438-31-0) help_outline Charge 2 Formula Fe InChIKeyhelp_outline CWYNVVGOOAEACU-UHFFFAOYSA-N SMILEShelp_outline [Fe++] 2D coordinates Mol file for the small molecule Search links Involved in 266 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,851 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 9,932 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (S)-2,3-epoxysqualene Identifier CHEBI:15441 Charge 0 Formula C30H50O InChIKeyhelp_outline QYIMSPSDBYKPPY-RSKUXYSASA-N SMILEShelp_outline CC(C)=CCC\C(C)=C\CC\C(C)=C\CC\C=C(/C)CC\C=C(/C)CC[C@@H]1OC1(C)C 2D coordinates Mol file for the small molecule Search links Involved in 32 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
Fe(III)-[cytochrome b5]
Identifier
RHEA-COMP:10439
Reactive part
help_outline
- Name help_outline Fe3+ Identifier CHEBI:29034 (CAS: 20074-52-6) help_outline Charge 3 Formula Fe InChIKeyhelp_outline VTLYFUHAOXGGBS-UHFFFAOYSA-N SMILEShelp_outline [Fe+3] 2D coordinates Mol file for the small molecule Search links Involved in 253 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,485 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:58916 | RHEA:58917 | RHEA:58918 | RHEA:58919 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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A widespread alternative squalene epoxidase participates in eukaryote steroid biosynthesis.
Pollier J., Vancaester E., Kuzhiumparambil U., Vickers C.E., Vandepoele K., Goossens A., Fabris M.
Steroids are essential triterpenoid molecules that are present in all eukaryotes and modulate the fluidity and flexibility of cell membranes. Steroids also serve as signalling molecules that are crucial for growth, development and differentiation of multicellular organisms<sup>1-3</sup>. The stero ... >> More
Steroids are essential triterpenoid molecules that are present in all eukaryotes and modulate the fluidity and flexibility of cell membranes. Steroids also serve as signalling molecules that are crucial for growth, development and differentiation of multicellular organisms<sup>1-3</sup>. The steroid biosynthetic pathway is highly conserved and is key in eukaryote evolution<sup>4-7</sup>. The flavoprotein squalene epoxidase (SQE) catalyses the first oxygenation reaction in this pathway and is rate limiting. However, despite its conservation in animals, plants and fungi, several phylogenetically widely distributed eukaryote genomes lack an SQE-encoding gene<sup>7,8</sup>. Here, we discovered and characterized an alternative SQE (AltSQE) belonging to the fatty acid hydroxylase superfamily. AltSQE was identified through screening of a gene library of the diatom Phaeodactylum tricornutum in a SQE-deficient yeast. In accordance with its divergent protein structure and need for cofactors, we found that AltSQE is insensitive to the conventional SQE inhibitor terbinafine. AltSQE is present in many eukaryotic lineages but is mutually exclusive with SQE and shows a patchy distribution within monophyletic clades. Our discovery provides an alternative element for the conserved steroid biosynthesis pathway, raises questions about eukaryote metabolic evolution and opens routes to develop selective SQE inhibitors to control hazardous organisms. << Less