Isomerases
Transferases | ||
---|---|---|
Enzyme classification | ||
EC, category | 5.-.-.- | |
Response type | Isomerization | |
Occurrence | ||
Parent taxon | Creature |
Isomerases are enzymes of the fifth enzyme class according to the systematic nomenclature of the enzyme commission of the International Union of Biochemistry (IUB) and catalyze the isomerization reactions, i.e. the conversion of a compound into an isomeric structure. Isomers are molecules with the same molecular formula but different absolute configuration or structural formula . Racemases catalyze racemization reactions in which a hydrogen is rearranged on the single chiral carbon atom of a compound. An important biochemical isomerization reaction is the aldose - ketose - rearrangement .
Isomerases are categorized in the EC number classification system under EC 5.-.-.- .
classification
EC number | feature | Group name | Examples |
---|---|---|---|
EC 5.1.-.- | Configuration inversion | Racemases and epimerases | UDP-glucose-4-epimerase |
EC 5.2.-.- | Configuration inversion | cis-trans isomerases | Peptidyl prolyl cis trans isomerase |
EC 5.3.-.- | Oxidoreduction | Intramolecular oxidoreductases | Glucose isomerase |
EC 5.4.-.- | Constitutional isomers | Mutases | Methylmalonyl-CoA mutase |
EC 5.5.-.- | Intramolecular lyases | Muconate cycloisomerase | |
EC 5.6.-.- | Changing polypeptides or DNA | Topoisomerases |
Other classes of enzymes
- Oxidoreductases ( EC 1.-.-.- )
- Transferases ( EC 2.-.-.- )
- Hydrolases ( EC 3.-.-.- )
- Lyases ( EC 4.-.-.- )
- Ligases ( EC 6.-.-.- )
Individual evidence
- ^ A b Albert Gossauer: Structure and reactivity of biomolecules , Verlag Helvetica Chimica Acta, Zurich, 2006, p. 450, ISBN 978-3-906390-29-1 .