Styrene-oxide isomerase
| Styrene-oxide isomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 5.3.99.7 | ||||||||
| CAS no. | 124541-89-5 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
Styrene-oxide isomerase (EC 5.3.99.7) is an enzyme that catalyzes the chemical reaction
The enzyme converts its substrate, styrene oxide, to phenylacetaldehyde. It belongs to the family of isomerases, specifically a class of other intramolecular oxidoreductases. The systematic name of this enzyme class is styrene-oxide isomerase (epoxide-cleaving).[1] This enzyme is also called SOI and participates in styrene degradation: the reaction is the second step of the pathway after the epoxidation of styrene by styrene monooxygenase.[2]
SOI is an integral membrane protein consisting of four transmembrane helices. It forms a novel homo-trimeric assembly, displaying a structural fold reminiscent of ion channels, as determined by cryogenic electron microscopy.[3]
The trimeric organization of SOI is essential for its function and is guided by the ferric heme b prosthetic group positioned at the interface of its subunits. This ferric heme b acts as a Lewis acid, interacting with the epoxide oxygen atom to facilitate epoxide ring-opening of substrates.[3]
References
- ↑ Enzyme 5.3.99.7 at KEGG Pathway Database.
- ↑ Hartmans, S.; Smits, J. P.; van der Werf, M. J.; Volkering, F.; de Bont, J. A. M. (November 1989). "Metabolism of Styrene Oxide and 2-Phenylethanol in the Styrene-Degrading Xanthobacter Strain 124X". Applied and Environmental Microbiology. 55 (11): 2850–2855. Bibcode:1989ApEnM..55.2850H. doi:10.1128/aem.55.11.2850-2855.1989. ISSN 0099-2240. PMC 203180. PMID 16348047.