Literature summary extracted from
Masuda, J.; Shibata, N.; Morimoto, Y.; Toraya, T.; Yasuoka, N.
How a protein generates a catalytic radical from coenzyme B(12): X-ray structure of a diol-dehydratase-adeninylpentylcobalamin complex (2000), Structure Fold. Des., 8, 775-788.
Cloned(Commentary)
EC Number |
Cloned (Comment) |
Organism |
---|
4.2.1.28 |
expression in Escherichia coli |
Klebsiella oxytoca |
Crystallization (Commentary)
EC Number |
Crystallization (Comment) |
Organism |
---|
4.2.1.28 |
sandwich-drop vapor diffusion method, 4ΒΊC |
Klebsiella oxytoca |
Organism
EC Number |
Organism |
UniProt |
Comment |
Textmining |
---|
4.2.1.28 |
Klebsiella oxytoca |
- |
- |
- |
Purification (Commentary)
EC Number |
Purification (Comment) |
Organism |
---|
4.2.1.28 |
chromatography on DEAE-cellulose |
Klebsiella oxytoca |
Reaction
EC Number |
Reaction |
Comment |
Organism |
Reaction ID |
---|
4.2.1.28 |
propane-1,2-diol = propanal + H2O |
binding of the substrate to the active site converts a hexacoordinated complex of K+ into the heptacoordinated one. A relatively large binding energy is released upon coordination of the two hydroxyl groups to K+, displacing a sixth ligand, H2O. Interaction of the coenzyme with the enzyme cleaves its Co-C bond, forming an adenosyl radical and cob(II)alamin. The radical abstracts the pro-S hydrogen of the S-enantiomer forming a substrate-derived radical and 5'-deoxyadenosine. The substrate-radical undergoes the 1,2-shift of the hydroxyl group, forming a product-derived gem-diol radical. The C2 of the product radical, abstracts a hydrogen back from deoxyadenosine with inversion of the configuration of C2, producing a 1,1-gem-diol, which undergoes dehydration, forming propionaldehyde and H2O |
Klebsiella oxytoca |
|
Substrates and Products (Substrate)
EC Number |
Substrates |
Comment Substrates |
Organism |
Products |
Comment (Products) |
Rev. |
Reac. |
---|
4.2.1.28 |
1,2-propanediol |
the substrate is located near to K+ rather than to the cobalt atom of cobalamin |
Klebsiella oxytoca |
propanal |
- |
? |
|
Cofactor
EC Number |
Cofactor |
Comment |
Organism |
Structure |
---|
4.2.1.28 |
coenzyme B12 |
adenosylcobalamin. There is a strict specificity of the enzyme for the coenzyme adenosyl group |
Klebsiella oxytoca |
|
4.2.1.28 |
additional information |
adeninylpentylcobalamin and cyanocobalamin are inactive as cofactors |
Klebsiella oxytoca |
|