ID   4.4.1.1
DE   cystathionine gamma-lyase.
AN   cystathionase.
AN   cystathioninase.
AN   cysteine desulfhydrase.
AN   cystine desulfhydrase.
AN   gamma-cystathionase.
AN   homoserine deaminase.
AN   homoserine dehydratase.
CA   H2O + L,L-cystathionine = 2-oxobutanoate + L-cysteine + NH4(+).
CC   -!- The enzyme cleaves a carbon-sulfur bond, releasing L-cysteine and an
CC       unstable enamine product that tautomerizes to an imine form, which
CC       undergoes a hydrolytic deamination to form 2-oxobutanoate and
CC       ammonia.
CC   -!- The latter reaction, which can occur spontaneously, can also be
CC       catalyzed by EC 3.5.99.10.
CC   -!- Also catalyzes the conversion of L-homoserine to 2-oxobutanoate and
CC       ammonia, of L-cystine to thiocysteine, pyruvate and ammonia, and of
CC       L-cysteine to pyruvate, hydrogen sulfide and ammonia.
CC   -!- Formerly EC 4.2.1.15.
DR   A5U908, CDS1_MYCTA ;  O69652, CDS1_MYCTU ;  P55216, CGL2_CAEEL ;
DR   F4K5T2, CGL_ARATH  ;  Q58DW2, CGL_BOVIN  ;  Q55DV9, CGL_DICDI  ;
DR   P32929, CGL_HUMAN  ;  Q60HG7, CGL_MACFA  ;  Q8VCN5, CGL_MOUSE  ;
DR   Q19QT7, CGL_PIG    ;  P18757, CGL_RAT    ;  P31373, CYS3_YEAST ;
DR   Q59829, CYSA_STRCO ;  O05394, MCCB_BACSU ;
//