Cloned (Comment) | Organism |
---|---|
gene cysK1, sequence comparisons, recombinant expression of N-terminally His6-tagged isozyme CysK1 in Escherichia coli strain BL21 (DE3) | Microcystis aeruginosa |
gene cysK2, sequence comparisons, recombinant expression of N-terminally His6-tagged isozyme CysK2 in Escherichia coli strain BL21 (DE3) | Microcystis aeruginosa |
Crystallization (Comment) | Organism |
---|---|
purified isozyme CysK1, hanging drop vapor diffusion technique, mixing of 10 mg/ml protein solution with an equal volume of reservoir solution containing 0.1 M MOPS, pH 6.0, 60% 2-methyl-2,4-pentanediol, 16°C, X-ray diffraction structure determination and analysis at 2.30 A resolution, molecular replacement using the coordinates of Mycobacterium tuberculosis OASS, PDB ID 2Q3B, as the search model | Microcystis aeruginosa |
purified isozyme CysK2 in complex with cystine, hanging drop vapor diffusion technique, mixing of 10 mg/ml protein solution with an equal volume of reservoir solution containing 1.5 M (NH4)2SO4, 0.1M Bis-Tris-propane, pH 7.0, and 10 mM cystine, 16°C, X-ray diffraction structure determination and analysis at 1.91 A resolution, molecular replacement using the coordinates of Mycobacterium tuberculosis OASS, PDB ID 2Q3B, as the search model | Microcystis aeruginosa |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
cystine | competitive versus O-acetyl-L-serine, the cystine-binding residues are highly conserved in all OASS proteins; competitive versus O-acetyl-L-serine, the cystine-binding residues are highly conserved in all OASS proteins. Active site of CysK2cystine binding structure, overview. Cystine occupies the substrate/product binding site of the enzyme | Microcystis aeruginosa | |
trichloroacetic acid | inactivation at 16.6% v/v; inactivation at 16.6% v/v | Microcystis aeruginosa |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa | |
1.1 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa | |
1.8 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
2.3 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
3.5 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa | |
4.8 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
O-acetyl-L-serine + hydrogen sulfide | Microcystis aeruginosa | - |
L-cysteine + acetate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Microcystis aeruginosa | A8YBP8 | gene cysK2, IPF_3084, or CAO86589 | - |
Microcystis aeruginosa | A8YBS4 | gene cysK1, IPF_2058, or cao86616 | - |
Purification (Comment) | Organism |
---|---|
recombinant N-terminally His6-tagged isozyme CysK1 from Escherichia coli strain BL21 (DE3) by nickel affinity chromatography and ultrafiltration | Microcystis aeruginosa |
recombinant N-terminally His6-tagged isozyme CysK2 from Escherichia coli strain BL21 (DE3) by nickel affinity chromatography and ultrafiltration | Microcystis aeruginosa |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
235 | - |
substrate O-acetyl-L-serine, purified recombinant isozyme CysK1, pH 7.0, 25°C | Microcystis aeruginosa |
412 | - |
substrate O-acetyl-L-serine, purified recombinant isozyme CysK2, pH 7.0, 25°C | Microcystis aeruginosa |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
O-acetyl-L-serine + hydrogen sulfide | - |
Microcystis aeruginosa | L-cysteine + acetate | - |
? |
Synonyms | Comment | Organism |
---|---|---|
O-acetylserine sulfhydrylase | - |
Microcystis aeruginosa |
OASS | - |
Microcystis aeruginosa |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
- |
Microcystis aeruginosa |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
132 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa | |
136 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
140 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa | |
211 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
231 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa | |
232 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Microcystis aeruginosa |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | dependent on, binding site structure analysis in a cleft between the N- and C-terminal domains, the phosphate group of PLP interacts with the highly conserved Gly/Thr-rich loop (G181TGGT185) and a water molecule, overview | Microcystis aeruginosa |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the family of fold-type II PLP-dependent enzymes. The cyanobacterium Microcystis aeruginosa PCC 7806 encodes three putative OASSs: CAO86616, CAO86589 and CAO86970, sequence comparisons | Microcystis aeruginosa |
metabolism | the O-acetylserine sulfhydrylase catalyzes the final step of cysteine biosynthesis from O-acetylserine and inorganic sulfide, negative feedback regulation of the pathway. Autoinhibition by cystine might be a universal mechanism of cysteine biosynthesis pathway | Microcystis aeruginosa |
metabolism | the O-acetylserine sulfhydrylase catalyzes the final step of cysteine biosynthesis from O-acetylserine and inorganic sulfide, negative feedback regulation of the pathway. Autoinhibition by cystine might be a universal mechanism of cysteine biosynthesis pathway, redox-dependent autoregulation | Microcystis aeruginosa |
additional information | three-dimensional structure comparisons of isozymes CysK1 and CysK2, overview | Microcystis aeruginosa |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
39.8 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa | |
48.1 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with glutathione, GSSG | Microcystis aeruginosa | |
76.5 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
91.3 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C | Microcystis aeruginosa | |
136 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa | |
219 | - |
O-acetyl-L-serine | recombinant enzyme, pH 7.0, 25°C, with DTT | Microcystis aeruginosa |