Lyases
| Lyases | ||
|---|---|---|
| Enzyme classification | ||
| EC, category | 4.-.-.- , lyases | |
| Response type | cleavage | |
| Substrate | ||
| Products | ||
| Occurrence | ||
| Parent taxon | Creature | |
Lyases are enzymes of the fourth class of enzymes , according to the systematic nomenclature of the enzyme commission of International Union of Biochemistry (IUB) and catalyze a cleavage of the molecule . Lyases occur in all living things. The reaction scheme:
Lyases produce a non- hydrolytic cleavage of a molecule into two products, usually with the formation of a double bond or a ring structure.
classification
Lyases are categorized in the EC number classification system under EC 4.-.-.- . Thereafter, lyases are further subdivided depending on what type of bond is broken:
| number | binding | example |
|---|---|---|
| EC 4.1.-.- | CC bond | Aldolase |
| EC 4.2.-.- | CO binding | Fumarase |
| EC 4.3.-.- | CN bond | Argininosuccinate lyase |
| EC 4.4.-.- | CS bond | Cystathionine β-lyase |
| EC 4.5.-.- | C-halogen bond | DDT dehydrochlorinase |
| EC 4.6.-.- | PO bond | Adenylyl cyclases |
| EC 4.7.-.- | CP binding |
Other classes of enzymes
- Oxidoreductases ( EC 1.-.-.- )
- Transferases ( EC 2.-.-.- )
- Hydrolases ( EC 3.-.-.- )
- Isomerases ( EC 5.-.-.- )
- Ligases ( EC 6.-.-.- )