Protein Variants | Comment | Organism |
---|---|---|
D282N | site-directed mutagenesis, while the wild-type mutant has residue R289 in a distal or a proximal conformation, the mutant shows R289 only in a distal conformation | Saccharomyces cerevisiae |
additional information | active site structures of wild-type and mutant enzymes, detailed overview | Saccharomyces cerevisiae |
Y254L | site-directed mutagenesis, while the wild-type mutant has residue R289 in a distal or a proximal conformation, the mutant shows R289 only in a distal conformation | Saccharomyces cerevisiae |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | steady-state kinetics | Saccharomyces cerevisiae |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrial intermembrane space | - |
Saccharomyces cerevisiae | 5758 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-lactate + 2 ferricytochrome c | Saccharomyces cerevisiae | the first step of the catalytic cycle consists of the oxidation of L-lactate by the FMN prosthetic group. FMN is later reoxidized by transferring its electrons one by one to the ferric heme. The final electron acceptor is cytochrome c | pyruvate + 2 ferrocytochrome c + 2 H+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharomyces cerevisiae | P00175 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
(S)-lactate + 2 ferricytochrome c = pyruvate + 2 ferrocytochrome c + 2 H+ | the hydride transfer mechanism involves the transfer of the lactate hydroxyl proton to H373 while the substrate aH atom is transferred as a hydride to the flavin mononucleotide (FMN) prosthetic group anchored in the active site | Saccharomyces cerevisiae |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-lactate + 2 ferricytochrome c | the first step of the catalytic cycle consists of the oxidation of L-lactate by the FMN prosthetic group. FMN is later reoxidized by transferring its electrons one by one to the ferric heme. The final electron acceptor is cytochrome c | Saccharomyces cerevisiae | pyruvate + 2 ferrocytochrome c + 2 H+ | - |
? | |
(S)-lactate + 2 flavocytochrome b2 | - |
Saccharomyces cerevisiae | pyruvate + 2 ferrocytochrome c + 2 H+ | - |
? |
Subunits | Comment | Organism |
---|---|---|
homotetramer | - |
Saccharomyces cerevisiae |
Synonyms | Comment | Organism |
---|---|---|
Fcb2 | - |
Saccharomyces cerevisiae |
L-lactate cytochrome c oxidoreductase | - |
Saccharomyces cerevisiae |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Saccharomyces cerevisiae |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.51 | - |
(S)-lactate | mutant Y254L with R289 distal, pH 7.0, 30°C | Saccharomyces cerevisiae | |
3.9 | - |
(S)-lactate | mutant D282N with R289 distal, pH 7.0, 30°C | Saccharomyces cerevisiae | |
270 | - |
(S)-lactate | wild-type enzyme with R289 distal, pH 7.0, 30°C | Saccharomyces cerevisiae |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Saccharomyces cerevisiae |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ferricytochrome c | - |
Saccharomyces cerevisiae | |
flavocytochrome b2 | - |
Saccharomyces cerevisiae | |
FMN | each of the four subunits contains a flavin mononucleotide prosthetic group | Saccharomyces cerevisiae | |
heme | each of the four subunits contains a beta-type heme | Saccharomyces cerevisiae | |
additional information | FMN and heme groups are localized in two different domains | Saccharomyces cerevisiae |
General Information | Comment | Organism |
---|---|---|
additional information | molecular dynamics simulations using a hybrid quantum mechanics/molecular mechanics (QM/MM) scheme to study the mechanism of L-lactate oxidation by flavocytochrome b2. Simulation results highlight the influence of the environment on the catalytic mechanism by describing a step-wise process in the wild-type enzyme with R289 in a distal position and a concerted mechanism for the other systems. Structure analysis of pyruvate in the Fcb2 active site pocket with R289 in the distal conformation. Residue Y254 plays a role in the catalytic process by stabilizing the product of the first proton transfer from substrate to H373, while residue D282 is expected to stabilize the imidazolium ion in transition and product states by electrostatic interactions and hydrogen bonding with the Hdelta of H373. Active site structures of wild-type and mutant enzymes, detailed overview | Saccharomyces cerevisiae |