CATH Classification

Domain Context

CATH Clusters

Superfamily 3.40.50.1100
Functional Family Threonine dehydratase catabolic

Enzyme Information

5.1.1.18
Serine racemase.
based on mapping to UniProt O59791
L-serine = D-serine.
-!- Highly selective for L-serine as substrate. -!- D-serine is found in type-II astrocytes in mammalian brain, where it appears to be an endogenous ligand of the glycine site of N-methyl-D- aspartate (NMDA) receptors. -!- The reaction can also occur in the reverse direction but does so more slowly at physiological serine concentrations.
4.3.1.17
L-serine ammonia-lyase.
based on mapping to UniProt O59791
L-serine = pyruvate + NH(3).
-!- The reaction catalyzed by both types of enzymes involves the initial elimination of water to form an enamine intermediate (hence the enzyme's original classification as EC 4.2.1.13) followed by tautomerization to an imine form and hydrolysis of the C-N bond. -!- The latter reaction, which can occur spontaneously, is also be catalyzed by EC 3.5.99.10. -!- This reaction is also carried out by EC 4.3.1.19 from a number of sources. -!- Formerly EC 4.2.1.13.
4.3.1.18
D-serine ammonia-lyase.
based on mapping to UniProt O59791
D-serine = pyruvate + NH(3).
-!- The enzyme cleaves a carbon-oxygen bond, releasing a water molecule (hence the enzyme's original classification as EC 4.2.1.14) and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. -!- The latter reaction, which can occur spontaneously, can also be catalyzed by EC 3.5.99.10. -!- Also acts, slowly, on D-threonine. -!- Formerly EC 4.2.1.14.

UniProtKB Entries (1)

O59791
SRR_SCHPO
Schizosaccharomyces pombe 972h-
Serine racemase

PDB Structure

PDB 1V71
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Crystal Structure of S.pombe Serine Racemase
Goto, M.
to be published