KEGG   ENZYME: 4.2.2.13Help
Entry
EC 4.2.2.13                 Enzyme                                 

Name
exo-(1->4)-alpha-D-glucan lyase;
alpha-(1->4)-glucan 1,5-anhydro-D-fructose eliminase;
alpha-1,4-glucan exo-lyase;
alpha-1,4-glucan lyase;
GLase
Class
Lyases;
Carbon-oxygen lyases;
Acting on polysaccharides
BRITE hierarchy
Sysname
(1->4)-alpha-D-glucan exo-4-lyase (1,5-anhydro-D-fructose-forming)
Reaction(IUBMB)
linear alpha-glucan = (n-1) 1,5-anhydro-D-fructose + D-glucose
Substrate
linear alpha-glucan
Product
(n-1) 1,5-anhydro-D-fructose;
D-glucose [CPD:C00031]
Comment
The enzyme catalyses the sequential degradation of (1->4)-alpha-D-glucans from the non-reducing end with the release of 1,5-anhydro-D-fructose. Thus, for an alpha-glucan containing n (1->4)-linked glucose units, the final products are 1 glucose plus (n-1) 1,5-anhydro-D-fructose. Maltose, maltosaccharides and amylose are all completely degraded. It does not degrade (1->6)-alpha-glucosidic bonds and thus the degradation of a branched glucan, such as amylopectin or glycogen, will result in the formation of 1,5-anhydro-D-fructose plus a limit dextrin. Other enzymes involved in the anhydrofructose pathway are EC 4.2.1.110 (aldos-2-ulose dehydratase), EC 4.2.1.111 (1,5-anhydro-D-fructose dehydratase) and EC 5.3.2.7 (ascopyrone tautomerase).
History
EC 4.2.2.13 created 1999
Reference
1  [PMID:8461323]
  Authors
Yu S, Kenne L, Pedersen M.
  Title
Alpha-1,4-glucan lyase, a new class of starch/glycogen degrading enzyme. I. Efficient purification and characterization from red seaweeds.
  Journal
Biochim. Biophys. Acta. 1156 (1993) 313-20.
Reference
2  [PMID:7763826]
  Authors
Yu S, Pedersen M.
  Title
Alpha-1,4-glucan lyase, a new class of starch/glycogen-degrading enzyme. II. Subcellular localization and partial amino-acid sequence.
  Journal
Planta. 191 (1993) 137-42.
Reference
3  [PMID:7766642]
  Authors
Yu S, Ahmad T, Kenne L, Pedersen M.
  Title
alpha-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. III. Substrate specificity, mode of action, and cleavage mechanism.
  Journal
Biochim. Biophys. Acta. 1244 (1995) 1-9.
Reference
4  [PMID:9187252]
  Authors
Yu S, Christensen TM, Kragh KM, Bojsen K, Marcussen J.
  Title
Efficient purification, characterization and partial amino acid sequencing of two alpha-1,4-glucan lyases from fungi.
  Journal
Biochim. Biophys. Acta. 1339 (1997) 311-20.
Reference
5  [PMID:10446355]
  Authors
Yu S, Bojsen K, Svensson B, Marcussen J.
  Title
alpha-1,4-glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to alpha-glucosidases.
  Journal
Biochim. Biophys. Acta. 1433 (1999) 1-15.
Reference
6  [PMID:11982345]
  Authors
Lee SS, Yu S, Withers SG.
  Title
alpha-1,4-Glucan lyase performs a trans-elimination via a nucleophilic displacement followed by a syn-elimination.
  Journal
J. Am. Chem. Soc. 124 (2002) 4948-9.
Reference
7  [PMID:14596624]
  Authors
Lee SS, Yu S, Withers SG.
  Title
Detailed dissection of a new mechanism for glycoside cleavage: alpha-1,4-glucan lyase.
  Journal
Biochemistry. 42 (2003) 13081-90.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
UM-BBD (Biocatalysis/Biodegradation Database): 
BRENDA, the Enzyme Database: 
CAS: 
148710-18-3

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