Structure of cyclodextrin glycosyltransferase complexed with a derivative of its main product beta-cyclodextrin.Schmidt, A.K., Cottaz, S., Driguez, H., Schulz, G.E.
(1998) Biochemistry 37: 5909-5915
- PubMed: 9558324
- DOI: 10.1021/bi9729918
- PubMed Abstract:
- Structure of Cyclodextrin Glycosyltransferase Refined at 2.0 A Resolution
Klein, C.,Schulz, G.E.
(1991) J.Mol.Biol. 217: 737
- Molecular Cloning, Nucleotide Sequence and Expression in Escherichia Coli of the Beta-Cyclodextrin Glycosyltransferase Gene from Bacillus Circulans Strain No. 8
Nitschke, L.,Heeger, K.,Bender, H.,Schulz, G.E.
(1990) Appl.Microbiol.Biotechnol. 33: 542
- Catalytic Center of Cyclodextrin Glycosyltransferase Derived from X-Ray Structure Analysis Combined with Site-Directed Mutagenesis
Klein, C.,Hollender, J.,Bender, H.,Schulz, G.E.
(1992) Biochemistry 31: 8740
Crystals of the inactive mutant Glu257-->Ala of cyclodextrin glycosyltransferase were soaked with the cyclodextrin (CD) derivative S-(alpha-D-glucopyranosyl)-6-thio-beta-CD. The structural analysis showed its beta-CD moiety with no density indication ...
Crystals of the inactive mutant Glu257-->Ala of cyclodextrin glycosyltransferase were soaked with the cyclodextrin (CD) derivative S-(alpha-D-glucopyranosyl)-6-thio-beta-CD. The structural analysis showed its beta-CD moiety with no density indication for the exocyclic glucosyl unit. For steric reasons, however, the position of this unit is restricted to be at only two of the seven glucosyl groups of beta-CD. The analysis indicated that the enzyme can cyclize branched alpha-glucans. The ligated beta-CD moiety revealed how the enzyme binds its predominant cyclic product. The conformation of the ligated beta-CD was intermediate between the more symmetrical conformation in beta-CD dodecahydrate crystals and the conformation of a bound linear alpha-glucan chain. Its scissile bond was displaced by 2.8 A from the position in linear alpha-glucans. Accordingly, the complex represents the situation after the cyclization reaction but before diffusion into the solvent, where a more symmetrical conformation is assumed, or the equivalent state in the reverse reaction. Furthermore, a unifying nomenclature for oligosaccharide-binding subsites in proteins is proposed.
Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Freiburg im Breisgau, Germany.