Structure of cyclodextrin glycosyltransferase refined at 2.0 A resolution

J Mol Biol. 1991 Feb 20;217(4):737-50. doi: 10.1016/0022-2836(91)90530-j.


The previously reported structural model of cyclodextrin glycosyltransferase (EC from Bacillus circulans has been improved. For this purpose the known sequence was built into an electron density map established by multiple isomorphous replacement and subsequent solvent-flattening at 2.5 A resolution. The resulting model was refined at 2.0 A resolution using a simulated annealing refinement method. Based on 70,171 independent reflections in the range 7.0 to 2.0 A resolution, a final R-factor of 17.6% was obtained with a model obeying standard geometry within 0.013 A in bond lengths and 2.7 degrees in bond angles. The final model consists of all 684 amino acid residues, two calcium ions and 588 solvent molecules.

MeSH terms

  • Amino Acid Sequence
  • Bacillus / enzymology*
  • Binding Sites
  • Calcium / metabolism
  • Glucosyltransferases / chemistry*
  • Glucosyltransferases / metabolism
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure
  • Protein Conformation
  • Solvents
  • Temperature
  • X-Ray Diffraction


  • Solvents
  • Glucosyltransferases
  • cyclomaltodextrin glucanotransferase
  • Calcium