5.2.1.14 | all-trans-beta-carotene = 9-cis-beta-carotene |
mechanism of isomerization catalysed by OsD27 involving a 1-electron transfer from the polyene p-system of beta-carotene to a [2Fe2S] cluster, generating a radical cation, which is able to rotate about the C-C single bond. Electron transfer back from the reduced [2Fe2S] cluster then generates the 9-cis-beta-carotene product. A mechanism involving single electron transfer from a [2Fe2S] cluster to form a radical anion intermediate is also possible. OsD27 retains catalytic activity under anaerobic conditions, therefore it does not require dioxygen for activity |
744876 |