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CATH Superfamily 3.40.50.1100

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was: waiting to be named.

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 5: Threonine dehydratase catabolic

There are 5 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Threonine ammonia-lyase. [EC: 4.3.1.19]
L-threonine = 2-oxobutanoate + 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 4.2.1.16), 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.
  • The enzymes from a number of sources also act on L-serine, cf. EC 4.3.1.17.
  • Formerly EC 4.2.1.16.
 27212 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0
(27202 more...)
L-serine ammonia-lyase. [EC: 4.3.1.17]
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.
 25512 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0 A0A023Z3F0
(25502 more...)
D-serine ammonia-lyase. [EC: 4.3.1.18]
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.
 32 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6
(22 more...)
Serine racemase. [EC: 5.1.1.18]
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.
 32 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0D9ZP07 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6 A0A0E0PCG6
(22 more...)
Threo-3-hydroxy-L-aspartate ammonia-lyase. [EC: 4.3.1.16]
Threo-3-hydroxy-L-aspartate = oxaloacetate + NH(3).
  • The enzyme, purified from the bacterium Pseudomonas sp. T62, is highly specific, and does not accept any other stereoisomer of 3-hydroxyaspartate.
  • Different from EC 4.3.1.20 and EC 4.3.1.27.
  • Requires a divalent cation such as Mn(2+), Mg(2+), or Ca(2+).
 13 A0A2N7XVT6 A0A2N7XVT6 A4F2N8 A4F2N8 G2WHH6 G2WHH6 G2WHH6 N1P2X9 N1P2X9 N1P2X9
(3 more...)