EC Number   |
Reaction |
Reference |
|---|
    4.1.99.11 | benzylsuccinate = toluene + fumarate |
benzylsuccinate synthase (BSS) catalyzes the formation of a C-C bond between toluene and fumarate by a radical mechanism, overview. An enzyme-bound glycyl radical cofactor transiently forms a catalytically essential enzyme-bound thiyl (Cys) radical |
749165 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
benzylsuccinate synthase (BSS) catalyzes the formation of a C-C bond between toluene and fumarate by a radical mechanism. BSS binds substrates in a buried active site and uses conformational changes to gate access. The C-C bond-forming reaction performed by BSS requires an oxygen-sensitive radical cofactor. BSS contains a backbone glycyl radical in its activated form. The two substrates adopt orientations that appear ideal for radical-mediated C-C bond formation, the methyl group of toluene is positioned between fumarate and a cysteine that forms a thiyl radical during catalysis, which is in turn adjacent to the glycine that serves as a radical storage residue. Toluene is held in place by fumarate on one face and tight packing by hydrophobic residues on the other face and sides. These hydrophobic residues appear to become ordered, thus encapsulating toluene, only in the presence of BSSbeta, a small protein subunit that forms a tight complex with BSSalpha, the catalytic subunit. Substrates can enter the active site through a channel, which can be blocked by subunit beta, BSSbeta plays a role in gating active site accessibility |
748195 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
DFT model of the reaction mechanism of BSS, mechanistic modeling |
-, 748432 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
mechanism |
678164 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
reaction mechanism of enzymatic radical C-C coupling by benzylsuccinate synthase, molecular dynamics (MD) simulations and quantum mechanics (QM) modeling, detailed overview. The enzyme is a glycyl radical enzyme that catalyzes the enantiospecific fumarate addition to toluene initiating its anaerobic metabolism in the denitrifying bacterium Thauera aromatica, and this reaction represents the general mechanism of toluene degradation in all known anaerobic degraders. The enantiospecificity of the enzyme seems to be enforced by a thermodynamic preference for binding of fumarate in the pro-(R)-orientation and reverse preference of benzyl radical attack on fumarate in pro-(S)-pathway which results with prohibitively high energy barrier of the radical quenching |
747978 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
stereospecific radical addition of toluene to fumarate, enzyme carries a stable organic free radical, most probably located on glycine residue 828 |
-, 210658 |
| 4.1.99.11 | benzylsuccinate = toluene + fumarate |
substrate binding stabilizing the active site and reaction mechanism via glycyl radical, detailed overview. Syn addition of toluene to fumaric acid and facilitation of a mechanism that retains the hydrogen abstracted from the methyl group of toluene within the succinyl moiety. The stability of substrates at the active site and the occurrence of feasible radical transfer distances between the thiyl radical, substrates, and the active site glycine indicate a substrate-assisted radical transfer pathway governing fumarate addition |
727687 |
