Cysteine synthase

{{infobox enzyme

| Name = cysteine synthase

| EC_number = 2.5.1.47

| CAS_number = 37290-89-4

| GO_code = 0004124

| image =

| width =

| caption =

}}

In enzymology, a cysteine synthase ({{EC number|2.5.1.47}}) is an enzyme that catalyzes the chemical reaction

:O³-acetyl-L-serine + hydrogen sulfide $\rightleftharpoons$ L-cysteine + acetate

Thus, the two substrates of this enzyme are O³-acetyl-L-serine and hydrogen sulfide, whereas its two products are L-cysteine and acetate.

This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is O3-acetyl-L-serine:hydrogen-sulfide 2-amino-2-carboxyethyltransferase. Other names in common use include O-acetyl-L-serine sulfhydrylase, O-acetyl-L-serine sulfohydrolase, O-acetylserine (thiol)-lyase, O-acetylserine (thiol)-lyase A, O-acetylserine sulfhydrylase, O3-acetyl-L-serine acetate-lyase (adding hydrogen-sulfide), acetylserine sulfhydrylase, cysteine synthetase, S-sulfocysteine synthase, 3-O-acetyl-L-serine:hydrogen-sulfide, and 2-amino-2-carboxyethyltransferase. This enzyme participates in 3 metabolic pathways: cysteine metabolism, selenoamino acid metabolism, and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.

Structural studies

As of late 2007, 12 structures have been solved for this class of enzymes, with PDB accession codes {{PDB link|1O58}}, {{PDB link|1VE1}}, {{PDB link|1Y7L}}, {{PDB link|1Z7W}}, {{PDB link|1Z7Y}}, {{PDB link|2BHS}}, {{PDB link|2BHT}}, {{PDB link|2EGU}}, {{PDB link|2ISQ}}, {{PDB link|2Q3B}}, {{PDB link|2Q3C}}, and {{PDB link|2Q3D}}.

References

{{cite journal | vauthors = Becker MA, Kredich NM, Tomkins GM | date = 1969 | title = The purification and characterization of O-acetylserine sulfhydrylase-A from Salmonella typhimurium | journal = J. Biol. Chem. | volume = 244 | pages = 2418–27 | pmid = 4891157 | issue = 9 | doi = 10.1016/S0021-9258(19)78240-4 | doi-access = free }}
{{cite journal | vauthors = Hara S, Payne MA, Schnackerz KD, Cook PF | date = 1990 | title = A rapid purification procedure and computer-assisted sulfide ion selective electrode assay for O-acetylserine sulfhydrylase from Salmonella typhimurium | journal = Protein Expr. Purif. | volume = 1 | pages = 70–6 | pmid = 2152186 | doi = 10.1016/1046-5928(90)90048-4 | issue = 1 }}
{{cite journal | vauthors = Ikegami F, Kaneko M, Lambein F, ((Kuo Y-H)), Murakoshi I | date = 1987 | title = Difference between uracilylalanine synthases and cysteine synthases in Pisum sativum | journal = Phytochemistry | volume = 26 | issue = 10 | pages = 2699–2704 | doi = 10.1016/S0031-9422(00)83575-X | bibcode = 1987PChem..26.2699I }}
{{cite journal | vauthors = Murakoshi I, Kaneko M, Koide C, Ikegami F | date = 1986 | title = Enzymatic-synthesis of the neuroexcitatory amino-acid quisqualic by cysteine synthase | journal = Phytochemistry | volume = 25 | issue = 12 | pages = 2759–2763 | doi = 10.1016/S0031-9422(00)83736-X }}
{{cite journal | vauthors = Tai CH, Burkhard P, Gani D, Jenn T, Johnson C, Cook PF | date = 2001 | title = Characterization of the allosteric anion-binding site of O-acetylserine sulfhydrylase | journal = Biochemistry | volume = 40 | pages = 7446–52 | pmid = 11412097 | doi = 10.1021/bi015511s | issue = 25 }}
{{cite journal | vauthors = Schnackerz KD, Hazlett TL, Gratton E, Mozzarelli A | date = 2000 | title = Role of pyridoxal 5'-phosphate in the structural stabilization of O-acetylserine sulfhydrylase | journal = J. Biol. Chem. | volume = 275 | pages = 40244–51 | pmid = 10995767 | doi = 10.1074/jbc.M007015200 | issue = 51 | doi-access = free }}

Category:EC 2.5.1

Category:Pyridoxal phosphate enzymes

Category:Enzymes of known structure