| cystathionine beta-lyase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Cystathionine beta-lyase tetramer, E.Coli | |||||||||
| Identifiers | |||||||||
| EC no. | 4.4.1.8 | ||||||||
| CAS no. | 9055-05-4 | ||||||||
| 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 / QuickGO | ||||||||
| |||||||||
Cystathionine beta-lyase (EC 4.4.1.8), also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction[1]
Thus, the substrate of this enzyme is L-cystathionine, whereas its 3 products are homocysteine, pyruvate, and ammonia.[2][3][4]
Found in plants, bacteria, and yeast, cystathionine beta-lyase is an essential part of the methionine biosynthesis pathway as homocysteine can be directly converted into methionine by methionine synthase.[3][5][6] The enzyme belongs to the γ-family of PLP-dependent enzymes due to its use of a pyridoxal-5'-phosphate (PLP) cofactor to cleave cystathionine.[7] The enzyme also belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cystathionine L-homocysteine-lyase (deaminating; pyruvate-forming). This enzyme participates in 5 metabolic pathways: methionine metabolism, cysteine metabolism, selenoamino acid metabolism, nitrogen metabolism, and sulfur metabolism.
- ^ Dwivedi CM, Ragin RC, Uren JR (June 1982). "Cloning, purification, and characterization of beta-cystathionase from Escherichia coli". Biochemistry. 21 (13): 3064–9. doi:10.1021/bi00256a005. PMID 7049234.
- ^ Flavin M, Slaughter C (July 1964). "Cystathionine Cleavage Enzymes of Neurospora". The Journal of Biological Chemistry. 239 (7): 2212–9. doi:10.1016/S0021-9258(20)82222-4. PMID 14209950.
- ^ a b Breitinger U, Clausen T, Ehlert S, Huber R, Laber B, Schmidt F, Pohl E, Messerschmidt A (June 2001). "The three-dimensional structure of cystathionine beta-lyase from Arabidopsis and its substrate specificity". Plant Physiology. 126 (2): 631–42. doi:10.1104/pp.126.2.631. PMC 111155. PMID 11402193.
- ^ Cite error: The named reference
Clausen_1997was invoked but never defined (see the help page). - ^ Cite error: The named reference
Droux_1995was invoked but never defined (see the help page). - ^ Messerschmidt A, Worbs M, Steegborn C, Wahl MC, Huber R, Laber B, Clausen T (March 2003). "Determinants of enzymatic specificity in the Cys-Met-metabolism PLP-dependent enzymes family: crystal structure of cystathionine gamma-lyase from yeast and intrafamiliar structure comparison". Biological Chemistry. 384 (3): 373–86. doi:10.1515/BC.2003.043. PMID 12715888. S2CID 24552794.
- ^ Alexander FW, Sandmeier E, Mehta PK, Christen P (February 1994). "Evolutionary relationships among pyridoxal-5'-phosphate-dependent enzymes. Regio-specific alpha, beta and gamma families". European Journal of Biochemistry. 219 (3): 953–60. doi:10.1111/j.1432-1033.1994.tb18577.x. PMID 8112347.