Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Zn2+ | RPE is activated by Zn2+ which binds with a stoichiometry of one ion per polypeptide | Streptococcus pyogenes |
Cloned (Comment) | Organism |
---|---|
the gene encoding RPE is expressed in the Escherichia coli strain BL21 (DE3) | Streptococcus pyogenes |
Crystallization (Comment) | Organism |
---|---|
crystal structure of the RPE is solved at 1.8 A resolution in the presence of D-xylitol 5-phosphate, an inert analogue of the D-xylulose 5-phosphate substrate. This structure suggests that the 2,3-enediolate intermediate in the 1,1-proton transfer reaction is stabilized by bidentate coordination to the Zn2+ that also is liganded to His 34, Asp 36, His 67, and Asp 176, the carboxylate groups of the Asp residues are positioned also to function as the acid/base catalysts | Streptococcus pyogenes |
Protein Variants | Comment | Organism |
---|---|---|
D176A | no detectable activity, substrate= 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes |
D36A | no detectable activity, substrate= 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes |
H34A | mutant discloses decreased affinity for Zn2+, kcat = 200/sec, substrate = 10 mM D-ribulose 5-phosphate, +10 micromol/l ZnCl2 | Streptococcus pyogenes |
H67A | mutant discloses decreased affinity for Zn2+, kcat = 270/sec, substrate = 10 mM D-ribulose 5-phosphate, +10 micromol/l ZnCl2 | Streptococcus pyogenes |
additional information | H34A, D36A, H67A, and D176A mutants are constructed since these His and Asp residues are strictly conserved in all RPEs and are observed to coordinate Zn2+ in the reported structures of the RPE from rice | Streptococcus pyogenes |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.2 | - |
D-ribulose 5-phosphate | - |
Streptococcus pyogenes |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | assay carried out at 10 mM Mg2+ | Streptococcus pyogenes |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Streptococcus pyogenes | Q9A1H8 | - |
- |
Purification (Comment) | Organism |
---|---|
lysate is applied to a chelating sepharose fast flow column charged with Ni2+, the N-terminal His tag is removed by thrombin cleavage | Streptococcus pyogenes |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-Ribulose 5-phosphate | - |
Streptococcus pyogenes | D-Xylulose 5-phosphate | - |
? |
Synonyms | Comment | Organism |
---|---|---|
D-ribulose 5-phosphate 3-epimerase | - |
Streptococcus pyogenes |
RPE | - |
Streptococcus pyogenes |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
100 | - |
D-ribulose 5-phosphate | RPE metal-free, stoichiometry of Zn2+: 0.1 ion per polypeptide, substrate 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes | |
200 | - |
D-ribulose 5-phosphate | mutant H34A, + 10 micromol/l ZnCl2 | Streptococcus pyogenes | |
270 | - |
D-ribulose 5-phosphate | mutant H67A, + 10 micromol/l ZnCl2 | Streptococcus pyogenes | |
480 | - |
D-ribulose 5-phosphate | RPE as isolated, stoichiometry of Zn2+: 0.3 ion per polypeptide, substrate 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes | |
840 | - |
D-ribulose 5-phosphate | RPE as isolated + 0.5 mM ZnCl2 present in assay, stoichiometry of Zn2+: 0.9 ion per polypeptide, substrate 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes | |
870 | - |
D-ribulose 5-phosphate | RPE metal-free + 0.5 mM ZnCl2 present in assay, stoichiometry of Zn2+: 0.9 ion per polypeptide, substrate 10 mM D-ribulose 5-phosphate | Streptococcus pyogenes |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Streptococcus pyogenes |