Cystathionine gamma-synthase

cystathionine gamma-synthase
Identifiers
EC number	2.5.1.48
CAS number	9030-70-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a cystathionine gamma-synthase (EC 2.5.1.48) is an enzyme that catalyzes the chemical reaction

O₄-succinyl-L-homoserine + L-cysteine $\rightleftharpoons$ L-cystathionine + succinate

Thus, the two substrates of this enzyme are O4-succinyl-L-homoserine and L-cysteine, whereas its two products are L-cystathionine and succinate.

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 O4-succinyl-L-homoserine:L-cysteine S-(3-amino-3-carboxypropyl)transferase. Other names in common use include O-succinyl-L-homoserine succinate-lyase (adding cysteine), O-succinylhomoserine (thiol)-lyase, homoserine O-transsuccinylase, O-succinylhomoserine synthase, O-succinylhomoserine synthetase, cystathionine synthase, cystathionine synthetase, homoserine transsuccinylase, 4-O-succinyl-L-homoserine:L-cysteine, and S-(3-amino-3-carboxypropyl)transferase. This enzyme participates in 4 metabolic pathways: methionine metabolism, cysteine metabolism, selenoamino acid metabolism, and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.

References

• Flavin M, Slaughter C (1967). "Enzymatic synthesis of homocysteine or methionine directly from O-succinyl-homoserine". Biochim. Biophys. Acta 132 (2): 400–5. doi:10.1016/0005-2744(67)90158-1. PMID 5340123.
• Kaplan MM, Flavin M (1966). "Cystathionine gamma-synthetase of Salmonella. Catalytic properties of a new enzyme in bacterial methionine biosynthesis". J. Biol. Chem. 241 (19): 4463–71. PMID 5922970.
• Wiebers JL, Garner HR (1967). "Homocysteine and cysteine synthetases of Neurospora crassa Purification, properties, and feedback control of activity". J. Biol. Chem. 242 (1): 12–23. PMID 6016326.
• Wiebers JL, Garner HR (1967). "Acyl derivatives of homoserine as substrates for homocysteine synthesis in Neurospora crassa, yeast, and Escherichia coli". J. Biol. Chem. 242 (23): 5644–9. PMID 12325384.
• Clausen T, Huber R, Prade L, Wahl MC, Messerschmidt A (1998). "Crystal structure of Escherichia coli cystathionine gamma-synthase at 1.5 A resolution". EMBO J. 17 (23): 6827–38. doi:10.1093/emboj/17.23.6827. PMC 1171030. PMID 9843488.
• Ravanel S, Gakiere B, Job D, Douce R. "Cystathionine gamma-synthase from Arabidopsis thaliana: purification and biochemical characterization of the recombinant enzyme overexpressed in Escherichia coli". Biochem. J. 331: 639–48. PMC 1219399. PMID 9531508.