spacer
View the latest EBI news stories and important announcements...
more

spacer
Search The CSA
PDB ID
UNIPROT ID
EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1bg6

E.C. nameopine dehydrogenase
SpeciesArthrobacter (Bacteria)
E.C. Number (IntEnz) 1.5.1.28
CSA Homologues of 1bg63c7a,3c7c,3c7d,
CSA Entries With UniProtID Q44297
CSA Entries With EC Number 1.5.1.28
PDBe Entry 1bg6
PDBSum Entry 1bg6
MACiE Entry 1bg6

Literature Report

IntroductionN-(1-D-carboxylethyl)-L-norvaline dehydrogenase is part of the (D,L) stereochemistry family of opine dehydrogenases and is able to catalyse the reaction of pyruvate with hydrophobic L amino acids to form opines through reductive condensation using NAD(P)H as a cofactor. Of particular interest is the stereochemical specificity of this enzyme as its reaction is a key step in a number of synthetic routes for pharmaceuticals. The enzyme displays some sequence homology with (L,L) opine dehydrogenases and both families display homology with 2-hydroxy acid dehydrogenases.
MechansimThe reaction is believed to proceed via nucleophilic attack by the L amino acid on the pyruvate with a histidine residue acting as a general acid, allowing the formation of a carbinolamine intermediate. Dehydration of this intermediate, again facilitated by acid-base action of Histidine, results in an imimine intermediate which is then reduced by hydride transfer from NAD(P)H to give the product.
Reaction

Catalytic Sites for 1bg6

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
AspA297297macie:sideChainActs to alter the pKa of His 202 to allow it to function as a general acid-base catalyst at physiological pH and thus catalyse the reaction efficiently. Thus is part of an Asp-His proton relay system.
HisA202202macie:sideChainProtonates the carbonyl oxygen resulting in a carbinolamine intermediate which proceeds via hydride transfer from the cofactor to form the product.

Literature References

Notes:Mechanism kinetics as yet unclear
Britton KL
Crystal structure and active site location of N-(1-D-carboxylethyl)-L-norvaline dehydrogenase.
Nat Struct Biol 1998 5 593-601
PubMed: 9665174
spacer
spacer