(1-4)-alpha-D-glucan:(1-4)-alpha-D-glucan 4-alpha-D-glycosyltransferase

EC no.
CAS no.9032-09-1
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, a 4-alpha-glucanotransferase (EC is an enzyme that catalyzes a chemical reaction that transfers a segment of a 1,4-alpha-D-glucan to a new position in an acceptor carbohydrate, which may be glucose or a 1,4-alpha-D-glucan.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase. Other names in common use include disproportionating enzyme, dextrin glycosyltransferase, D-enzyme, debranching enzyme maltodextrin glycosyltransferase, amylomaltase, and dextrin transglycosylase. This enzyme participates in starch and sucrose metabolism in plants.[1][2] Studies of the enzyme from potato led to the discovery of cycloamylose.[3]

Structural studies[]

As of late 2007, 14 structures have been solved for this class of enzymes, with PDB accession codes 1CWY, 1ESW, 1FP8, 1FP9, 1K1W, 1K1X, 1K1Y, 1LWH, 1LWJ, 1TZ7, 1X1N, 2OWC, 2OWW, and 2OWX.


  1. ^ Critchley, Joanna H.; Zeeman, Samuel C.; Takaha, Takeshi; Smith, Alison M.; Smith, Steven M. (2001-04-01). "A critical role for disproportionating enzyme in starch breakdown is revealed by a knock-out mutation in Arabidopsis". The Plant Journal. 26 (1): 89–100. doi:10.1046/j.1365-313x.2001.01012.x. ISSN 1365-313X. PMID 11359613.
  2. ^ Chia, Tansy; Thorneycroft, David; Chapple, Andrew; Messerli, Gaëlle; Chen, Jychian; Zeeman, Samuel C.; Smith, Steven M.; Smith, Alison M. (2004-03-01). "A cytosolic glucosyltransferase is required for conversion of starch to sucrose in Arabidopsis leaves at night". The Plant Journal. 37 (6): 853–863. doi:10.1111/j.1365-313X.2003.02012.x. ISSN 1365-313X. PMID 14996213.
  3. ^ Takaha, Takeshi; Yanase, Michiyo; Takata, Hiroki; Okada, Shigetaka; Smith, Steven M. (1996-02-09). "Potato D-enzyme Catalyzes the Cyclization of Amylose to Produce Cycloamylose, a Novel Cyclic Glucan". Journal of Biological Chemistry. 271 (6): 2902–2908. doi:10.1074/jbc.271.6.2902. ISSN 0021-9258. PMID 8621678.