ENTRY       EC 4.4.1.8
NAME        Cystathionine beta-lyase
            beta-Cystathionase
            Cystine lyase
CLASS       Lyases
            Carbon-sulfur lyases
SYSNAME     Cystathione L-homocysteine-lyase (deaminating)
REACTION    Cystathionine + H2O = L-Homocysteine + NH3 + Pyruvate
SUBSTRATE   Cystathionine
            L-Cystine
            H2O
PRODUCT     L-Homocysteine
            NH3
            Pyruvate
            Cysteine persulfide
COFACTOR    Pyridoxal phosphate
COMMENT     A pyridoxal-phosphate protein. The enzyme from some sources also
            acts on L-cystine, forming pyruvate, ammonia and cysteine
            persulfide, and a number of related compounds. Possibly identical,
            in yeast, with EC 4.4.1.6
            (EC 4.4.1.6 S-Alkylcysteine lyase)
PATHWAY     PATH: MAP00271  Methionine metabolism
            PATH: MAP00272  Cysteine metabolism
            PATH: MAP00450  Selenoamino acid metabolism
            PATH: MAP00910  Nitrogen metabolism
            PATH: MAP00920  Sulfur metabolism
MOTIF       PS: PS00868  [DQ]-[LIVM]-x(3)-[STAGC](2)-T-K-[FYW]-[LIVMF]-x-G-H-
                         [SGN]
GENES       ECO: b3008(metC)
            HIN: HI0122(metC)
            SCE: YFR055W
DBLINKS     University of Geneva ENZYME DATA BANK: 4.4.1.8
            WIT (What Is There) Metabolic Reconstruction: 4.4.1.8
///