Cloned (Comment) | Organism |
---|---|
gene GAOA, phylogenetic tree | Fusarium graminearum |
Crystallization (Comment) | Organism |
---|---|
wild-type enzyme and W290F mutant enzyme crystal structure analysis, PDB IDs 2EIE and 2EIC, respectively | Fusarium graminearum |
Protein Variants | Comment | Organism |
---|---|---|
W290F | structure PDB ID 2EIC, comparison to the wild-type enzyme. The activity of Trp290 mutants of FgrGalOx show a dramatic loss of oxidative capacity compared to wild-type, which is correlated to significantly higher Km values for the natural substrate galactose with the FgrGalOx W290G/F mutants, presumably because of the loss of a hydrogen-bonding interaction between W290 and a remote hydroxyl group of the substrate. Trp290 in FgrGalOx is implicated in stabilizing the radical form of the Cys-Tyr cofactor, although substitution with either Phe or Gly also stabilizes the tyrosine radical with retention of catalytic activity, while other substitutions were detrimental to the enzyme | Fusarium graminearum |
W290G | the activity of Trp290 mutants of FgrGalOx show a dramatic loss of oxidative capacity compared to wild-type, which is correlated to significantly higher Km values for the natural substrate galactose with the FgrGalOx W290G/F mutants, presumably because of the loss of a hydrogen-bonding interaction between W290 and a remote hydroxyl group of the substrate. Trp290 in FgrGalOx is implicated in stabilizing the radical form of the Cys-Tyr cofactor, although substitution with either Phe or Gly also stabilizes the tyrosine radical with retention of catalytic activity, while other substitutions were detrimental to the enzyme | Fusarium graminearum |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cu2+ | essentially required, binding site structure, residues Cys228 and Tyr272 in FgrGalOx are linked via a thioether bond. An inactive, oxidized state of FgrGalOx, which contains a Cu(II) site and a 1-electron reduced Cys-Tyr cofactor, produce a low-temperature EPR spectrum, this inactive state can be activated under typical assay conditions | Fusarium graminearum |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-galactose + O2 | Fusarium graminearum | - |
D-galacto-hexodialdose + H2O2 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Fusarium graminearum | P0CS93 | i.e. Gibberella zeae, formerly Dactylium dendroides | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
D-galactose + O2 = D-galacto-hexodialdose + H2O2 | the first half-reaction involves proton transfer from O-6 of galactose to the axial tyrosine anion, hydrogen atom transfer (HAT) from C-6 of galactose to the tyrosine-cysteine radical cofactor and electron transfer from the carbohydrate to generate the aldehyde and Cu(I). To complete the catalytic cycle, the second half-reaction is proposed to involve inner-sphere electron transfer from Cu(I) to oxygen to yield superoxide, HAT from the phenolic hydroxyl group of the Tyr-Cys cofactor to the superoxide to produce metal-bound hydroperoxide and proton transfer from the axial tyrosine to hydroperoxide to produce hydrogen peroxide and the re-oxidized, active Cu(II)-radical state of the enzyme | Fusarium graminearum |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-galactose + O2 | - |
Fusarium graminearum | D-galacto-hexodialdose + H2O2 | - |
? | |
additional information | benzyl alcohol is also a substrate for the enzyme | Fusarium graminearum | ? | - |
? | |
raffinose + O2 | - |
Fusarium graminearum | 6''-aldehydoraffinose + 6''-carboxyraffinose + H2O2 + H2O | - |
? | |
xyloglucan + O2 | - |
Fusarium graminearum | ? + H2O2 | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | the enzyme contains two domains, one is the N-terminal CBM32 domain, tertiary structure comparison | Fusarium graminearum |
Synonyms | Comment | Organism |
---|---|---|
FgrGalOx | - |
Fusarium graminearum |
galactose 6-oxidase | - |
Fusarium graminearum |
GAOA | gene name, UniProt | Fusarium graminearum |
GOase | UniProt | Fusarium graminearum |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
23 | - |
assay at | Fusarium graminearum |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
two ionizable groups involved in catalysis with basic pH optima | Fusarium graminearum |
8 | - |
assay at | Fusarium graminearum |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
Cys-Tyr cofactor | an inactive, oxidized state of FgrGalOx, which contains a Cu(II) site and a 1-electron reduced Cys-Tyr cofactor, produce a low-temperature EPR spectrum, this inactive state can be activated under typical assay conditions | Fusarium graminearum |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the the galactose 6-oxidase/glyoxal oxidase family of mononuclear copper-radical oxidases, auxiliary activity family 5, AA5, subfamily 2, AA5_2. Structure-function analysis and comparison to other structurally related but catalytically inactive members of the family, from Colletotrichum graminicola and Colletotrichum gloeosporioides, CgrAlcOx and CglAlcOx, reveals catalytic diversity in the galactose oxidase and glyoxal oxidase family, overview. All AA5 sequences known to date contain the key active site residues of FgrGalOx, namely, C228 and Y272 | Fusarium graminearum |
additional information | the key active site residues of FgrGalOx, C228 and Y272, combine to form the unique crosslinked thioether-tyrosyl cofactor, and Y495, H496 and H581 that also coordinate to the copper ion. Another key active site is tryptophan W290in FgrGalOx. The N-terminal CBM32 domain binds galactosyl residues. Structure-function analysis of wild-type and mutant enzymes, overview | Fusarium graminearum |