Cystathionine beta-synthase

From Wikipedia, the free encyclopedia

In enzymology, a cystathionine beta-synthase (EC 4.2.1.22) is an enzyme that catalyzes the chemical reaction

L-serine + L-homocysteine $\rightleftharpoons$ L-cystathionine + H₂O

Thus, the two substrates of this enzyme are L-serine and L-homocysteine, whereas its two products are L-cystathionine and H₂O.

This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is L-serine hydro-lyase (adding homocysteine; L-cystathionine-forming). Other names in common use include serine sulfhydrase, beta-thionase, methylcysteine synthase, cysteine synthase, serine sulfhydrylase, and L-serine hydro-lyase (adding homocysteine). This enzyme participates in 4 metabolic pathways: glycine, serine and threonine metabolism, methionine metabolism, selenoamino acid metabolism, and huntington's disease. It employs one cofactor, pyridoxal phosphate.

1 Structural studies
2 References
3 External links
- 3.1 Gene Ontology (GO) codes

[edit] Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1JBQ and 1M54.

[edit] References

IUBMB entry for 4.2.1.22
BRENDA references for 4.2.1.22 (Recommended.)
PubMed references for 4.2.1.22
PubMed Central references for 4.2.1.22
Google Scholar references for 4.2.1.22
LL (1971). "Specificity and some other properties of liver serine sulphhydrase: evidence for its identity with cystathionine -synthase". Biochim. Biophys. Acta. 242: 247–60. PMID 5121611.
Nakagawa H, Kimura H (1968). "Purification and properties of cystathionine synthetase synthetase from rat liver: separation of cystathionine synthetase from serine dehydratase". Biochem. Biophys. Res. Commun. 32: 209–14. PMID 5672136.
SCHLOSSMANN K, BRUEGGEMANN J, LYNEN F (1962). "[Biosynthesis of cysteine. I. Detection and isolation of serine sulfhydrase from baker's yeast.]". Biochem. Z. 336: 258–73. PMID 13991884.