Phosphoketolase
| phosphoketolase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC number | 4.1.2.9 | ||||||||
| CAS number | 9031-75-8 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / EGO | ||||||||
| |||||||||
In enzymology, a phosphoketolase (EC 4.1.2.9) is an enzyme that catalyzes the chemical reaction
- D-xylulose 5-phosphate + phosphate
acetyl phosphate + D-glyceraldehyde 3-phosphate + H2O
Thus, the two substrates of this enzyme are D-xylulose 5-phosphate and phosphate, whereas its 3 products are acetyl phosphate, D-glyceraldehyde 3-phosphate, and H2O.
This enzyme belongs to the family of lyases, specifically the aldehyde-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is D-xylulose-5-phosphate D-glyceraldehyde-3-phosphate-lyase (adding phosphate; acetyl-phosphate-forming). Other names in common use include D-xylulose-5-phosphate D-glyceraldehyde-3-phosphate-lyase, and (phosphate-acetylating). This enzyme participates in 3 metabolic pathways: pentose phosphate pathway, methane metabolism, and carbon fixation. It employs one cofactor, thiamin diphosphate.
References
- HEATH EC, HURWITZ J, HORECKER BL, GINSBURG A (1958). "Pentose fermentation by Lactobacillus plantarum. I. The cleavage of xylulose 5-phosphate by phosphoketolase". J. Biol. Chem. 231 (2): 1009–29. PMID 13539033.
- Schramm M, Klybas V and Racker E (1958). "Phospholytic cleavage of fructose-6-phosphate by fructose-6-phosphate phosphoketolase from Acetobacter xylinum". J. Biol. Chem. 233: 1283–1288.