Cystathionine beta-synthase

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

:L-serine + L-homocysteine $ightleftharpoons$ 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.

tructural studies

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

References

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External links

::"The CAS registry number for this enzyme class is CAS registry|9023-99-8."

Gene Ontology (GO) codes