Protein Variants | Comment | Organism |
---|---|---|
W315A | site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme. The extra space afforded by the absence of the Trp315 wall possibly lowers the free energy barrier of the cyclization step of the catalytic mechanism, allowing product release to become rate-limiting | Aspergillus fumigatus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Michaelis-Menten kinetics and kinetic solvent viscosity effects with wild-type and mutant enzymes. A strong dependence of the kcat value on solution viscosity is observed when UDP-beta-L-arabinofuranose is used as the substrate with the wild-type enzyme | Aspergillus fumigatus | |
0.094 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus | |
0.193 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus | |
0.45 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus | |
0.7 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-alpha-D-galactopyranose | Aspergillus fumigatus | - |
UDP-alpha-D-galactofuranose | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Aspergillus fumigatus | Q4W1X2 | i.e. Neosartorya fumigata | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
UDP-alpha-D-galactopyranose = UDP-alpha-D-galactofuranose | catalytic reaction mechanism, detailed overview. A covalent adduct is formed between the substrate and the FADH cofactor, temporarily breaking the glycosidic bond, followed by an internal proton transfer between N5FADH and O6FADH. The next step involves linearization of the sugar and formation of the iminium ion species. In the next step, the sugar cyclizes into its five-membered ring form. This step is isotope sensitive and is considered to be the chemical rate-limiting step of the mechanism. Once the furanose form of the sugar is reached, another internal proton transfer takes place, and the glycosidic bond to UDP is formed. Finally, the product of the reaction exits the active site of the enzyme | Aspergillus fumigatus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-alpha-D-galactofuranose | - |
Aspergillus fumigatus | UDP-alpha-D-galactopyranose | - |
r | |
UDP-alpha-D-galactopyranose | - |
Aspergillus fumigatus | UDP-alpha-D-galactofuranose | - |
r | |
UDP-beta-L-arabinofuranose | - |
Aspergillus fumigatus | UDP-beta-L-arabinopyranose | - |
r | |
UDP-beta-L-arabinopyranose | - |
Aspergillus fumigatus | UDP-beta-L-arabinofuranose | - |
r |
Synonyms | Comment | Organism |
---|---|---|
AfUGM | - |
Aspergillus fumigatus |
glfA | - |
Aspergillus fumigatus |
UGM | - |
Aspergillus fumigatus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Aspergillus fumigatus |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.14 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus | |
0.23 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus | |
0.27 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus | |
100 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Aspergillus fumigatus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | a flavoenzyme, FAD is tightly bound, binding kinetics and mechanism | Aspergillus fumigatus |
General Information | Comment | Organism |
---|---|---|
additional information | molecular dynamics simulations. Binding modes of substrates in the active site of enzyme AfUGM | Aspergillus fumigatus |
physiological function | galactofuranose (Galf) biosynthesis begins with the conversion of UDP-galactopyranose (UDP-Galp) to UDP-Galf as a rate-limiting step catalyzed by the flavoenzyme UDP-galactopyranose mutase (UGM). Enzyme UGM is essential for the survival and proliferation of several pathogens. UGM from the pathogenic fungus Aspergillus fumigatus also catalyzes the isomerization of UDP-arabinopyranose (UDP-Arap), which differs from UDPGalp by lacking a -CH2-OH substituent at the C5 position of the hexose ring | Aspergillus fumigatus |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.33 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus | |
1.4 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant mutant W315A | Aspergillus fumigatus | |
1.489 | - |
UDP-beta-L-arabinofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus | |
222.22 | - |
UDP-alpha-D-galactofuranose | pH 7.0, 37°C, recombinant wild-type enzyme | Aspergillus fumigatus |