show all | hide all No of entries

Information on EC 4.3.1.19 - threonine ammonia-lyase

for references in articles please use BRENDA:EC4.3.1.19
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
EC Tree
     4 Lyases
         4.3 Carbon-nitrogen lyases
             4.3.1 Ammonia-lyases
                4.3.1.19 threonine ammonia-lyase
IUBMB Comments
Most enzymes that catalyse this reaction are pyridoxal-phosphate-dependent, although some enzymes contain an iron-sulfur cluster instead. The reaction catalysed 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, threonine dehydratase), followed by tautomerization to an imine form and hydrolysis of the C-N bond [3,5]. The latter reaction, which can occur spontaneously, is also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase . The enzymes from a number of sources also act on L-serine, cf. EC 4.3.1.17, L-serine ammonia-lyase.
Specify your search results
Select one or more organisms in this record:
Word Map
The enzyme appears in viruses and cellular organisms
Reaction Schemes
hide(Overall reactions are displayed. Show all >>)
Synonyms
threonine deaminase, sactd, sp0454, threonine dehydratase/deaminase, l-tdh, threonine dehydrase, ec 4.2.1.16, threonine deaminase/dehydratase, more
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
2-aminobut-2-enoate = 2-iminobutanoate
show the reaction diagram
(1b), spontaneous
-
-
-
2-iminobutanoate + H2O = 2-oxobutanoate + NH3
show the reaction diagram
(1c), spontaneous
-
-
-
L-threonine = 2-aminobut-2-enoate + H2O
show the reaction diagram
(1a)
-
-
-
L-threonine = 2-oxobutanoate + NH3
show the reaction diagram
(overall reaction); that from P. putida is not. The enzyme from a number of sources also acts on L-serine, cf. EC 4.3.1.17, L-serine ammonia-lyase. The reaction catalysed probably involves initial elimination of water, hence the enzyme's original classification as EC 4.2.1.16, threonine dehydratase, followed by isomerization and hydrolysis of the product with C-N bond breakage; The enzyme from many sources is a pyridoxal-phosphate protein
-
-
-