Cloned (Comment) | Organism |
---|---|
gene algE4, recombinant expression in Escherichia coli strain ER2566, and expression of chimeric enzyme mutant AlgE64 | Azotobacter vinelandii |
gene algE6, recombinant expression in Escherichia coli strain ER2566, and expression of chimeric enzyme mutant AlgE64, recombinant expression of the R-modules, AlgE6R1, AlgE6R2, and AlgE6R3 | Azotobacter vinelandii |
Protein Variants | Comment | Organism |
---|---|---|
additional information | exchanging the R-modules between AlgE4 and AlgE6 resulted in a novel epimerase called AlgE64 with increased G-block forming ability compared with AlgE6 | Azotobacter vinelandii |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
[mannuronan]-beta-D-mannuronate | Azotobacter vinelandii | - |
[alginate]-alpha-L-guluronate | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Azotobacter vinelandii | Q44493 | - |
- |
Azotobacter vinelandii | Q9ZFH0 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant enzyme AlgE4 and chimeric enzyme mutant AlgE64 from Escherichia coli strain ER2566 by chitin affinity chromatography, dialysis, and gel filtration | Azotobacter vinelandii |
recombinant enzyme AlgE6 and chimeric enzyme mutant AlgE64, and of recombinant R-modules from Escherichia coli strain ER2566 by chitin affinity chromatography, dialysis, and gel filtration | Azotobacter vinelandii |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | alginate binding ability of the R-modules of AlgE4 by NMR and isothermal titration calorimetry, overview. Titration of the R-modules with defined alginate oligomers shows strong interaction between AlgE4R and both oligo-M and MG | Azotobacter vinelandii | ? | - |
? | |
additional information | alginate binding ability of the R-modules of AlgE6 by NMR and isothermal titration calorimetry, overview. Titration of the R-modules with defined alginate oligomers shows no interaction between these oligomers and the individual R-modules from AlgE6. Acombination of all three R-modules from AlgE6 shows weak interaction with long M-oligomers | Azotobacter vinelandii | ? | - |
? | |
[mannuronan]-beta-D-mannuronate | - |
Azotobacter vinelandii | [alginate]-alpha-L-guluronate | - |
r |
Subunits | Comment | Organism |
---|---|---|
More | the alginate epimerases display a modular structure composed of one or two catalytic A-modules and from one to seven R-modules having an activating effect on the A-module, NMR structure of overall structure of AlgE4 (AR) using small angle x-ray scattering. Small angle x-ray scattering analyses of AlgE4 and AlgE6 show an overall elongated shape with some degree of flexibility between the modules for both enzymes | Azotobacter vinelandii |
More | the alginate epimerases display a modular structure composed of one or two catalytic A-modules and from one to seven R-modules having an activating effect on the A-module, NMR structure of the individual R-modules from AlgE6 (AR1R2R3) and the overall structure of AlgE6 using small angle x-ray scattering, PDB IDs 2ML1, 2ML2, and 2ML3. The AlgE6 R-modules fold into an elongated parallel beta-roll with a shallow, positively charged groove across the module. Small angle x-ray scattering analyses of AlgE4 and AlgE6 show an overall elongated shape with some degree of flexibility between the modules for both enzymes | Azotobacter vinelandii |
Synonyms | Comment | Organism |
---|---|---|
AlgE4 | - |
Azotobacter vinelandii |
AlgE6 | - |
Azotobacter vinelandii |
General Information | Comment | Organism |
---|---|---|
evolution | the bacterium Azotobacter vinelandii produces a family of seven secreted and calcium-dependent mannuronan C-5 epimerases (AlgE1-7) | Azotobacter vinelandii |
additional information | alginate epimerases consist of catalytic and noncatalytic domains. The noncatalytic domains of AlgE4 and AlgE6 possess different alginate binding behavior despite highly similar structures. Noncatalytic subunits of AlgE6 and AlgE4 influence the product specificity of the catalytic domain | Azotobacter vinelandii |
physiological function | alginate is produced as poly-M and then certain M residues are converted to G by epimerases acting on the polymer level. The alginate-producing bacterium Azotobacter vinelandii has one periplasmic epimerase, which incorporates single G residues into the alginate during secretion of the polymer. In addition, Azotobacter vinelandii produces seven extracellular C-5 alginate epimerases called AlgE1-7. Each of the epimerases convert mannuronic acid to guluronic acid in different patterns. The secreted and calcium-dependent mannuronan C-5 epimerases in Azotobacter vinelandii are responsible for epimerization of beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G) in alginate polymers | Azotobacter vinelandii |
physiological function | alginate is produced as poly-M and then certain M residues are converted to G by epimerases acting on the polymer level. The alginate-producing bacterium Azotobacter vinelandii has one periplasmic epimerase, which incorporates single G residues into the alginate during secretion of the polymer. In addition, Azotobacter vinelandii produces seven extracellular C-5 alginate epimerases called AlgE1-7. Each of the epimerases converts mannuronic acid to guluronic acid in different patterns. The secreted and calcium-dependent mannuronan C-5 epimerases in Azotobacter vinelandii are responsible for epimerization of beta-D-mannuronic acid (M) to alpha-L-guluronic acid (G) in alginate polymers | Azotobacter vinelandii |