EC 188.8.131.52 - Aldos-2-ulose dehydratase
IntEnz Enzyme Nomenclature
1,5-anhydro-D-fructose dehydratase (microthecin-forming)
- (1) 1,5-anhydro-D-fructose = 2-hydroxy-2-(hydroxymethyl)-2H-pyran-3(6H)-one + H2O
- (1a) 1,5-anhydro-D-fructose = 1,5-anhydro-4-deoxy-D-glycero-hex-3-en-2-ulose + H2O
- (1b) 1,5-anhydro-4-deoxy-D-glycero-hex-3-en-2-ulose = 2-hydroxy-2-(hydroxymethyl)-2H-pyran-3(6H)-one
This enzyme catalyses two of the steps in the anhydrofructose pathway, which leads to the degradation of glycogen and starch via 1,5-anhydro-D-fructose [1,2]. Aldose-2-uloses such as 2-dehydroglucose can also act as substrates, but more slowly [1,2,4]. This is a bifunctional enzyme that acts as both a lyase and as an isomerase . Differs from EC 184.108.40.206, which can carry out only reaction (1a), is inhibited by its product and requires metal ions for activity .
Links to other databases
The anhydrofructose pathway and its possible role in stress response and signaling.Biochim. Biophys. Acta 1760 : 1314-1322 (2006). [PMID: 16822618]
Enzymatic description of the anhydrofructose pathway of glycogen degradation II. Gene identification and characterization of the reactions catalyzed by aldos-2-ulose dehydratase that converts 1,5-anhydro-D-fructose to microthecin with ascopyrone M as the intermediate.Biochim. Biophys. Acta 1723 : 63-73 (2005). [PMID: 15716041]
Presence of microthecin in the red alga Gracilariopsis lemaneiformis and its formation from 1,5-anhydro-D-fructose.Phytochemistry 41 : 151-154 (1996).
Pyranosone dehydratase from the basidiomycete Phanerochaete chrysosporium: improved purification, and identification of 6-deoxy-D-glucosone and D-xylosone reaction products.Arch. Microbiol. 160 : 27-34 (1993). [PMID: 8352649]
Enzymatic description of the anhydrofructose pathway of glycogen degradation. I. Identification and purification of anhydrofructose dehydratase, ascopyrone tautomerase and α-1,4-glucan lyase in the fungus Anthracobia melaloma.Biochim. Biophys. Acta 1672 : 120-129 (2004). [PMID: 15110094]
[EC 220.127.116.11 created 2006]