CATH Classification

Domain Context

CATH Clusters

Superfamily Aspartate Aminotransferase, domain 1
Functional Family Cystathionine beta-lyase

Enzyme Information

4.4.1.28
L-cysteine desulfidase.
based on mapping to UniProt P06721
L-cysteine + H(2)O = sulfide + NH(3) + pyruvate.
-!- The enzyme from the archaeon Methanocaldococcus jannaschii contains a [4Fe-4S] cluster and is specific for L-cysteine (cf. EC 4.4.1.1). -!- It cleaves a carbon-sulfur bond releasing sulfide and the unstable enamine product 2-aminoprop-2-enoate that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. -!- The same reaction can also be catalyzed by some pyridoxal-phosphate proteins (cf. EC 4.4.1.1).
4.4.1.13
Cysteine-S-conjugate beta-lyase.
based on mapping to UniProt P06721
An L-cysteine-S-conjugate + H(2)O = RSH + NH(3) + pyruvate.
-!- A pyridoxal 5'-phosphate protein. -!- The enzyme is promiscuous regarding the moiety conjugated to L-cysteine, and can accept both aliphatic and aromatic substitutions. -!- The enzyme cleaves a carbon-sulfur bond, releasing a thiol and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. -!- While bacteria and plants have dedicated enzymes, all of the animal enzymes discovered thus far are bifunctional, most of which also act as aminotransferases. -!- Formerly EC 4.4.1.6 and EC 4.4.1.8.

UniProtKB Entries (1)

P06721
METC_ECOLI
Escherichia coli K-12
Cystathionine beta-lyase MetC

PDB Structure

PDB 2FQ6
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Inhibitors of bacterial cystathionine beta-lyase: leads for new antimicrobial agents and probes of enzyme structure and function.
Ejim, L.J., Blanchard, J.E., Koteva, K.P., Sumerfield, R., Elowe, N.H., Chechetto, J.D., Brown, E.D., Junop, M.S., Wright, G.D.
J.Med.Chem.