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
Thus, the substrate of this enzyme is  L-cystathionine, whereas its 3 products are homocysteine, pyruvate, and ammonia.

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.
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.
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.
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
Thus, the substrate of this enzyme is  L-cystathionine, whereas its 3 products are homocysteine, pyruvate, and ammonia.
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. 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. 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.
Cystathionine beta-lyase