EC Number |
Substrates |
Organism |
Products |
Reversibility |
---|
2.5.1.73 | more |
two-step Cys-tRNACys formation: in organisms like Archaeoglobus fulgidus lacking a canonical cysteinyl-tRNA synthetase for the direct Cys-tRNACys formation, Cys-tRNACys is produced by the indirect pathway, in which the non-canonical O-phosphoseryl-tRNA synthetase, SepRS, ligates the non-canonical amino acid O-phosphoserine, Sep, to tRNACys, and the Sep-tRNA:Cys-tRNA synthase converts the produced Sep-tRNACys to Cys-tRNACys, overview, the SepRS/SepCysS pathway is the sole route for cysteine biosynthesis in the organism |
Archaeoglobus fulgidus |
? |
- |
? |
2.5.1.73 | more |
the active site contains an internal aldimine Lys209-PLP and the sulfate ion, SepCysS should not bind Sep-tRNASec and discriminate tRNACys from tRNASec on the basis of the differences in the length of the T-arms, or SepCysS recognizes the discriminator sequence, which is Ura73 in tRNACys and Gua73 in tRNASec, overview |
Archaeoglobus fulgidus |
? |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfate |
- |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfate |
evolutionary history of Cys-tRNACys formation, overview |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfate |
the in vivo sulfur donor is not determined |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfide |
- |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfide |
modeling of tRNA binding, overview, sulfide, persulfide, and thiosulfate, but not cysteine, can function as sulfur donor in vitro, the active site is located deep within the large, basic cleft to accommodate Sep-tRNACys, binding modeling of Sep-tRNACys, overview, possibly the side-chain of a Cys residue in SepCysS becomes persulfided as a sulfur transfer intermediate state |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfide |
the sulfur donor for this enzyme is unknown though in vitro sulfide is sufficient |
Archaeoglobus fulgidus |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNACys + sulfide |
- |
Escherichia coli |
L-cysteinyl-tRNACys + phosphate |
- |
? |
2.5.1.73 | O-phospho-L-seryl-tRNASec + sulfide |
selenocysteinyl-specific O-phospho-L-seryl-tRNASec is recognized as a substrate, presence of the O-phospho-L-seryl moiety is crucial for recognition |
Escherichia coli |
L-cysteinyl-tRNASec + phosphate |
- |
? |