This family includes enzymes involved in cysteine and methionine metabolism. The following are members: Cystathionine gamma-lyase, Cystathionine gamma-synthase, Cystathionine beta-lyase, Methionine gamma-lyase, OAH/OAS sulfhydrylase, O-succinylhomoserine sulfhydrylase All of these members participate is slightly different reactions. All these enzymes use PLP (pyridoxal-5'-phosphate) as a cofactor.

1: Crystal structure of the pyridoxal-5'-phosphate dependent cystathionine beta-lyase from Escherichia coli at 1.83 A. Clausen T, Huber R, Laber B, Pohlenz HD, Messerschmidt A; J Mol Biol 1996;262:202-224. PMID:8831789

2: Crystal structure of Escherichia coli cystathionine gamma-synthase at 1.5 A resolution. Clausen T, Huber R, Prade L, Wahl MC, Messerschmidt A; EMBO J 1998;17:6827-6838. PMID:9843488