EC Number   |
Reaction |
Reference |
|---|
    2.5.1.65 | O-phospho-L-serine + hydrogen sulfide = L-cysteine + phosphate |
a pyridoxal-phosphate protein, the enzyme from Aeropyrum pernix acts on both O-phospho-L-serine and O3-acetyl-L-serine, in contrast with EC 2.5.1.47, cysteine synthase, which acts only on O3-acetyl-L-serine |
654085 |
| 2.5.1.65 | O-phospho-L-serine + hydrogen sulfide = L-cysteine + phosphate |
active site structure, modeling of substrate binding at the active site with Arg297 being crucial for activity |
659728 |
| 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 |
-, 738534 |
| 2.5.1.65 | O-phospho-L-serine + hydrogen sulfide = L-cysteine + phosphate |
ping-pong bi-bi mechanism |
-, 655576, 737868 |
| 2.5.1.65 | O-phospho-L-serine + hydrogen sulfide = L-cysteine + phosphate |
ping-pong bi-bi mechanism, the active site of ApOPSS contains pyridoxal 5'-phosphate linked to lysine 127 as an internal Schiff base. Binding of the primary substrate O-phospho-L-serine displaces the lysine and forms an external Schiff base, initiating the first half-reaction that yields an alpha-aminoacrylate intermediate linked to pyridoxal 5'-phosphate. The second half-reaction involves the addition of a secondary substrate to the alpha-aminoacrylate intermediate and generates an external Schiff base with cysteine. The active-site lysine reacts with this external Schiff base, releasing cysteine and regenerating the internal Schiff base with K127. When other nucleophiles are used instead of sulfide, enzyme ApOPSS produces the corresponding non-natural amino acid |
-, 738193 |
