EC Number | Cloned (Comment) | Organism |
---|---|---|
2.5.1.65 | gene cysK2 or Rv0848, recombinant expression of N-terminally His6-tagged enzyme in Escherichia coli strain BL21(DE3) | Mycobacterium tuberculosis |
EC Number | Protein Variants | Comment | Organism |
---|---|---|---|
2.5.1.65 | additional information | construction of truncated variant CysK2NT | Mycobacterium tuberculosis |
2.5.1.65 | R243A | site-directed mutagenesis, the mutant shows increased activity compared to the wild-type enzyme | Mycobacterium tuberculosis |
EC Number | KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
2.5.1.65 | additional information | - |
additional information | stopped-flow and Michaelis-Menten kinetic analysis, overview. The amino acrylate reaction intermediate is not stable and decomposes with a pseudo-first-order rate constant kobs of 0.12/s | Mycobacterium tuberculosis | |
2.5.1.65 | 0.044 | - |
thiosulfate | pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.135 | - |
O-phospho-L-serine | dephosphorylation, pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.214 | - |
thiosulfate | pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.374 | - |
thiosulfate | dephosphorylation, pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.485 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 1.085 | - |
O-phospho-L-serine | dephosphorylation, pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 1.086 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis |
EC Number | Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
2.5.1.65 | O-phospho-L-serine + thiosulfate | Mycobacterium tuberculosis | CysK2 utilizes O-phospho-L-serine and thiosulfate as acceptor and preferred sulfur donor substrates in a pyridoxal 5'-phosphate-dependent reaction resulting in the formation of S-sulfocysteine | S-sulfocysteine + phosphate | - |
? | |
2.5.1.65 | O-phospho-L-serine + thiosulfate | Mycobacterium tuberculosis H37Rv | CysK2 utilizes O-phospho-L-serine and thiosulfate as acceptor and preferred sulfur donor substrates in a pyridoxal 5'-phosphate-dependent reaction resulting in the formation of S-sulfocysteine | S-sulfocysteine + phosphate | - |
? |
EC Number | Organism | UniProt | Comment | Textmining |
---|---|---|---|---|
2.5.1.65 | Mycobacterium tuberculosis | Q79FV4 | gene cysK2 or Rv0848 | - |
2.5.1.65 | Mycobacterium tuberculosis H37Rv | Q79FV4 | gene cysK2 or Rv0848 | - |
EC Number | Purification (Comment) | Organism |
---|---|---|
2.5.1.65 | recombinant N-terminally His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography and desalting gel filtration, followed by cleavage of the His-tag using thrombin and tag elimination through another sequence of nickel affinity chromatography and gel filtration | Mycobacterium tuberculosis |
EC Number | Reaction | Comment | Organism | Reaction ID |
---|---|---|---|---|
2.5.1.65 | O-phospho-L-serine + hydrogen sulfide = L-cysteine + phosphate | catalytic cycle of CysK2 and related cysteine synthases, catalytic raction mechanism of enzyme CysK2 via formation of the enzyme-aminoacrylate intermediate, accompanied by the release of a phosphate ion, commonly observed in the class of pyridoxal 5'-phosphate-dependent enzymes, overview | Mycobacterium tuberculosis |
EC Number | Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
2.5.1.65 | additional information | the enzyme uses a mechanism via a central aminoacrylate intermediate that is similar to that of other members of this pyridoxal 5'-phosphate-dependent enzyme family. Enzyme CysK2 does not utilize thiocarboxylated CysO as a sulfur donor but accepts thiosulfate and sulfide as donor substrates, the specificity constant kcat/Km of CysK2 for thiosulfate is 40fold higher than for sulfide, suggesting an annotation as S-sulfocysteine synthase. No significant activity with O-acetyl-L-serine, Asp, Val, Gln, Glu, Ser, Asn, Cys, Ser, Leu, homocysteine, ketoacids such as pyruvate and 2-oxoglutarate, amino acid precursors like 3-phosphoglycerate and succinate, and derivatives like N-acetylcysteine and diaminopimelic acid | Mycobacterium tuberculosis | ? | - |
? | |
2.5.1.65 | additional information | the enzyme uses a mechanism via a central aminoacrylate intermediate that is similar to that of other members of this pyridoxal 5'-phosphate-dependent enzyme family. Enzyme CysK2 does not utilize thiocarboxylated CysO as a sulfur donor but accepts thiosulfate and sulfide as donor substrates, the specificity constant kcat/Km of CysK2 for thiosulfate is 40fold higher than for sulfide, suggesting an annotation as S-sulfocysteine synthase. No significant activity with O-acetyl-L-serine, Asp, Val, Gln, Glu, Ser, Asn, Cys, Ser, Leu, homocysteine, ketoacids such as pyruvate and 2-oxoglutarate, amino acid precursors like 3-phosphoglycerate and succinate, and derivatives like N-acetylcysteine and diaminopimelic acid | Mycobacterium tuberculosis H37Rv | ? | - |
? | |
2.5.1.65 | O-phospho-L-serine + thiosulfate | - |
Mycobacterium tuberculosis | S-sulfocysteine + phosphate | - |
? | |
2.5.1.65 | O-phospho-L-serine + thiosulfate | CysK2 utilizes O-phospho-L-serine and thiosulfate as acceptor and preferred sulfur donor substrates in a pyridoxal 5'-phosphate-dependent reaction resulting in the formation of S-sulfocysteine | Mycobacterium tuberculosis | S-sulfocysteine + phosphate | - |
? | |
2.5.1.65 | O-phospho-L-serine + thiosulfate | - |
Mycobacterium tuberculosis H37Rv | S-sulfocysteine + phosphate | - |
? | |
2.5.1.65 | O-phospho-L-serine + thiosulfate | CysK2 utilizes O-phospho-L-serine and thiosulfate as acceptor and preferred sulfur donor substrates in a pyridoxal 5'-phosphate-dependent reaction resulting in the formation of S-sulfocysteine | Mycobacterium tuberculosis H37Rv | S-sulfocysteine + phosphate | - |
? |
EC Number | Subunits | Comment | Organism |
---|---|---|---|
2.5.1.65 | dimer | in solution | Mycobacterium tuberculosis |
EC Number | Synonyms | Comment | Organism |
---|---|---|---|
2.5.1.65 | CysK2 | - |
Mycobacterium tuberculosis |
2.5.1.65 | O-phospho-L-serine-dependent S-sulfocysteine synthase | - |
Mycobacterium tuberculosis |
2.5.1.65 | O-phosphoserine S-sulfocysteine synthase | - |
Mycobacterium tuberculosis |
2.5.1.65 | S-sulfocysteine synthase | - |
Mycobacterium tuberculosis |
EC Number | Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|---|
2.5.1.65 | 21 | 22 | assay at | Mycobacterium tuberculosis |
EC Number | Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
2.5.1.65 | 0.0067 | - |
O-phospho-L-serine | dephosphorylation, pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.2 | - |
O-phospho-L-serine | dephosphorylation, pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.457 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.913 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis |
EC Number | pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|---|
2.5.1.65 | 7 | - |
assay at | Mycobacterium tuberculosis |
2.5.1.65 | 9 | - |
the pH optimum for the dephosphorylation reaction is around pH 9.0, most likely because the spontaneous hydrolysis of the aminoacrylate intermediate is faster at this pH value, resulting in an increased turnover rate in the absence of the sulfur donor | Mycobacterium tuberculosis |
EC Number | Cofactor | Comment | Organism | Structure |
---|---|---|---|---|
2.5.1.65 | pyridoxal 5'-phosphate | dependent on | Mycobacterium tuberculosis |
EC Number | General Information | Comment | Organism |
---|---|---|---|
2.5.1.65 | metabolism | two biosynthetic routes to L-cysteine, each with its own specific cysteine synthase (CysK1 and CysM), are described in Mycobacterium tuberculosis, and a third putative sulfhydrylase in this pathogen, CysK2, is an S-sulfocysteine synthase, utilizing O-phosphoserine (OPS) and thiosulfate as substrates. Mycobacterial CysK2 thus provides a third metabolic route to cysteine, either directly using sulfide as donor or indirectly via S-sulfocysteine, cysteine synthasis pathways overview | Mycobacterium tuberculosis |
2.5.1.65 | physiological function | the enzyme synthesizes S-sulfocysteine, the can also act as a signaling molecule triggering additional responses in redox defense in the pathogen upon exposure to reactive oxygen species during dormancy | Mycobacterium tuberculosis |
EC Number | kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
2.5.1.65 | additional information | - |
additional information | the specificity constant kcat/Km of CysK2 for thiosulfate is 40fold higher than for sulfide | Mycobacterium tuberculosis | |
2.5.1.65 | 0.841 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 0.942 | - |
O-phospho-L-serine | pH 7.0, 22°C, recombinant mutant R243A enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 1.16 | - |
O-phospho-L-serine | dephosphorylation, pH 7.0, 22°C, recombinant wild-type enzyme | Mycobacterium tuberculosis | |
2.5.1.65 | 3.97 | - |
O-phospho-L-serine | apparent second-order rate of the first half-reaction, pH 7.0, 21°C, recombinant wild-type enzyme | Mycobacterium tuberculosis |