1d3c

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spinqualitylabelsall models PDB ID 1d3c Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
, resolution 1.78Å
Ligands:	, ,
Activity:	Cyclomaltodextrin glucanotransferase, with EC number 2.4.1.19
Related:	1CDG, 1CXI, 1CXF, 1CXK, 1CXL, 2DIJ
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

MICHAELIS COMPLEX OF BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE WITH GAMMA-CYCLODEXTRIN

Overview

The enzyme cyclodextrin glycosyltransferase is closely related to alpha-amylases but has the unique ability to produce cyclodextrins (circular alpha(1-->4)-linked glucoses) from starch. To characterize this specificity we determined a 1.8-A structure of an E257Q/D229N mutant cyclodextrin glycosyltransferase in complex with its product gamma-cyclodextrin, which reveals for the first time how cyclodextrin is competently bound. Across subsites -2, -1, and +1, the cyclodextrin ring binds in a twisted mode similar to linear sugars, giving rise to deformation of its circular symmetry. At subsites -3 and +2, the cyclodextrin binds in a manner different from linear sugars. Sequence comparisons and site-directed mutagenesis experiments support the conclusion that subsites -3 and +2 confer the cyclization activity in addition to subsite -6 and Tyr-195. On this basis, a role of the individual residues during the cyclization reaction cycle is proposed.

About this Structure

1D3C is a Single protein structure of sequence from Bacillus circulans. Full crystallographic information is available from OCA.

Reference

The cyclization mechanism of cyclodextrin glycosyltransferase (CGTase) as revealed by a gamma-cyclodextrin-CGTase complex at 1.8-A resolution., Uitdehaag JC, Kalk KH, van Der Veen BA, Dijkhuizen L, Dijkstra BW, J Biol Chem. 1999 Dec 3;274(49):34868-76. PMID:10574960

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