Industrial Biotransformations

2.2 Enzyme Classes
EC 5.4 Intramolecular transferases (mutases)
This enzyme subclass can be divided in two groups.
The enzymes belonging to 5.4.1 and 5.4.2 catalyze the transfer of a functional group
from one oxygen atom to another oxygen atom of the same molecule.
TG
O OH
R 1
n
R 2
R 1
TG
OH O
TG = transferred groups are acyl or orthophosphate groups
R 1,2 = organic residue
n = 0 or 4
n
R 2
The enzymes classified as 5.4.3 catalyze the transfer of a whole amino group from one
carbon atom of a molecule to a neighboring atom of the same molecule.
R 1
NH 2
R 2
R 1,2 = organic residue
EC 5.5 Intramolecular lyases
X
R 1
R 2
H
X = O, CH 2
R 1,2 = organic residue
2.2.6
EC 6 Ligases
HX
R 1
R 2
H
R 1
NH 2
R 2
In contrast to all other five enzyme classes this last main division in the Enzyme Nomenclature
is the only one where no member is used for the production of any fine chemicals
in an industrial process. Nevertheless, these biocatalysts play a major role in genetic engineering
or genetic diagnostics, as specific enzymes in this class that are known as DNA
ligases catalyze the formation of C–O bonds in DNA synthesis. This reaction is essential
59