Isomerase

In biochemistry, an isomerase is a protein that catalyses the interconversion of polymers. Isomerases thus catalyze reactions of the form

A → B

Nomenclature

The names of isomerases are formed as "substrate isomerase" (for example, enoyl CoA isomerase), or as "substrate type of isomerase" (for example, phosphoglucomutase).

Classification

Isomerases are classified as EC 5 in the EC number classification of enzymes. Isomerases can be further classified into six subclasses:

• EC 5.1 includes enzymes that catalyze racemization (racemases) and epimerization (epimerases)
• EC 5.2 includes enzymes that catalyze the isomerization of geometric isomers (cis-trans isomerases)
• EC 5.3 includes intramolecular oxidoreductases
• EC 5.4 includes intramolecular transferases (mutases)
• EC 5.5 includes intramolecular lyases
• EC 5.99 includes other isomerases (including topoisomerases)

References

• EC 5 Introduction from the Department of Chemistry at Queen Mary, University of London