Literature summary extracted from
Szaleniec, M.; Heider, J.
Modeling of the reaction mechanism of enzymatic radical C-C coupling by benzylsuccinate synthase (2016), Int. J. Mol. Sci., 17, 514 .
Activating Compound
EC Number |
Activating Compound |
Comment |
Organism |
Structure |
---|
4.1.99.11 |
additional information |
enzyme BSS needs to be posttranslationally activated to the active, radical-containing state by a separate activating enzyme, which is encoded in a common operon with the genes for the BSS subunits and belongs to the family of S-adenosyl-methionine-dependent radical enzymes |
Thauera aromatica |
|
Application
EC Number |
Application |
Comment |
Organism |
---|
4.1.99.11 |
environmental protection |
enzyme BSS and the growing number of additional fumarate-adding enzymes have become model cases for environmental processes in contaminated soils and deep anoxic subsediment habitats, and their isotopic preferences and conserved sequences serving as templates for molecular probes are employed as tools for monitoring these processes in situ |
Thauera aromatica |
Metals/Ions
EC Number |
Metals/Ions |
Comment |
Organism |
Structure |
---|
4.1.99.11 |
Fe2+ |
one low potential [4Fe4S]-cluster is located in each of the two small subunits |
Thauera aromatica |
|
Natural Substrates/ Products (Substrates)
EC Number |
Natural Substrates |
Organism |
Comment (Nat. Sub.) |
Natural Products |
Comment (Nat. Pro.) |
Rev. |
Reac. |
---|
4.1.99.11 |
toluene + fumarate |
Thauera aromatica |
- |
benzylsuccinate |
- |
? |
|
Organism
EC Number |
Organism |
UniProt |
Comment |
Textmining |
---|
4.1.99.11 |
Thauera aromatica |
O87943 AND O87944 AND O87942 |
alpha-, beta-, and gamma-subunit |
- |
Posttranslational Modification
EC Number |
Posttranslational Modification |
Comment |
Organism |
---|
4.1.99.11 |
additional information |
enzyme BSS needs to be posttranslationally activated to the active, radical-containing state by a separate activating enzyme, which is encoded in a common operon with the genes for the BSS subunits and belongs to the family of S-adenosyl-methionine-dependent radical enzymes |
Thauera aromatica |
Reaction
EC Number |
Reaction |
Comment |
Organism |
Reaction ID |
---|
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 |
Thauera aromatica |
|
Substrates and Products (Substrate)
EC Number |
Substrates |
Comment Substrates |
Organism |
Products |
Comment (Products) |
Rev. |
Reac. |
---|
4.1.99.11 |
additional information |
docking of the substrates into the relaxed active site and structure of the enzyme-product complex, overview. The active site cavity contains two hydrophobic regions, which are involved in interacting with the benzene ring and the protonated carboxyl group, respectively. On the other hand, a hydrophilic portion of the active site cavity binds the deprotonated carboxylic group by a strong electrostatic interaction towards Arg508 and a range of hydrogen bonds. Kinetic isotope effect of 4.0 for [2H] substituents at the methyl group of toluene |
Thauera aromatica |
? |
- |
? |
|
4.1.99.11 |
toluene + fumarate |
- |
Thauera aromatica |
benzylsuccinate |
- |
? |
|
4.1.99.11 |
toluene + fumarate |
the enzyme generates enantiospecifically (R)-benzylsuccinate from fumarate and toluene |
Thauera aromatica |
benzylsuccinate |
- |
r |
|
Subunits
EC Number |
Subunits |
Comment |
Organism |
---|
4.1.99.11 |
heterotrimer |
1 * 100000 + 1 * 8500 + 1 * 6500, the enzyme consists of three subunits encoded by three different genes and of very different sizes: the large subunit of circa 100 kDa contains the glycyl radical in the active site and presumably carries out the catalysis, whereas the two small subunits of 8.5 and 6.5 kDa each contain a low-potential [4Fe4S]-cluster |
Thauera aromatica |
Synonyms
EC Number |
Synonyms |
Comment |
Organism |
---|
4.1.99.11 |
BSS |
- |
Thauera aromatica |
4.1.99.11 |
BSSA |
- |
Thauera aromatica |
Cofactor
EC Number |
Cofactor |
Comment |
Organism |
Structure |
---|
4.1.99.11 |
[4Fe-4S] cluster |
one low potential [4Fe4S]-cluster is located in each of the two small subunits |
Thauera aromatica |
|
General Information
EC Number |
General Information |
Comment |
Organism |
---|
4.1.99.11 |
additional information |
structure homology modeling |
Thauera aromatica |
4.1.99.11 |
physiological function |
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 |
Thauera aromatica |