EC 4.2.2.13 - Exo-(1→4)-α-D-glucan lyase

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IntEnz Enzyme Nomenclature
EC 4.2.2.13

Names

Accepted name:
exo-(1→4)-α-D-glucan lyase
Other names:
α-(1→4)-glucan 1,5-anhydro-D-fructose eliminase
α-1,4-glucan exo-lyase
α-1,4-glucan lyase
exo-α-1,4-glucan lyase
exo-(1,4)-α-D-glucan lyase
α-1,4-glucan 1,5-anhydro-D-fructose eliminase
Systematic name:
(1→4)-α-D-glucan exo-4-lyase (1,5-anhydro-D-fructose-forming)

Reaction

Comments:

The enzyme catalyses the sequential degradation of (1→4)-α-D-glucans from the non-reducing end with the release of 1,5-anhydro-D-fructose. Thus, for an α-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)-α-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).

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0047457
CAS Registry Number: 148710-18-3

References

  1. Yu, S., Kenne, L. and Pedersén, M.
    α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. I. Efficient purification and characterization from red seaweeds.
    Biochim. Biophys. Acta 1156: 313-320 (1993). [PMID: 8461323]
  2. Yu, S. and Pedersén, M.
    α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. II. Subcellular localization and partial amino-acid sequence.
    Planta 191: 137-142 (1993).
  3. Yu, S., Ahmad, T., Kenne, L. and Pedersén, M.
    α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. III. Substrate specificity, mode of action, and cleavage mechanism.
    Biochim. Biophys. Acta 1244: 1-9 (1995). [PMID: 7766642]
  4. Yu, S., Christensen, T.M.I.E., Kragh, K.M., Bojsen, K. and Marcussen, J.
    Efficient purification, characterization and partial amino acid sequencing of two α-1,4-glucan lyases from fungi.
    Biochim. Biophys. Acta 1339: 311-320 (1997). [PMID: 9187252]
  5. Yu, S., Bojsen, K., Svensson, B. and Marcussen, J.
    α-1,4-glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to α-glucosidases.
    Biochim. Biophys. Acta 1433: 1-15 (1999). [PMID: 10446355]
  6. Lee, S.S., Yu, S. and Withers, S.G.
    α-1,4-Glucan lyase performs a trans-elimination via a nucleophilic displacement followed by a syn-elimination.
    J. Am. Chem. Soc. 124: 4948-4949 (2002). [PMID: 11982345]
  7. Lee, S.S., Yu, S. and Withers, S.G.
    Detailed dissection of a new mechanism for glycoside cleavage: α-1,4-glucan lyase.
    Biochemistry 42: 13081-13090 (2003). [PMID: 14596624]

[EC 4.2.2.13 created 1999]