1TCM

CYCLODEXTRIN GLYCOSYLTRANSFERASE W616A MUTANT FROM BACILLUS CIRCULANS STRAIN 251


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The raw starch binding domain of cyclodextrin glycosyltransferase from Bacillus circulans strain 251.

Penninga, D.van der Veen, B.A.Knegtel, R.M.van Hijum, S.A.Rozeboom, H.J.Kalk, K.H.Dijkstra, B.W.Dijkhuizen, L.

(1996) J.Biol.Chem. 271: 32777-32784


  • PubMed Abstract: 
  • The E-domain of cyclodextrin glycosyltransferase (CGTase) (EC 2.4.1.19) from Bacillus circulans strain 251 is a putative raw starch binding domain. Analysis of the maltose-dependent CGTase crystal structure revealed that each enzyme molecule containe ...

    The E-domain of cyclodextrin glycosyltransferase (CGTase) (EC 2.4.1.19) from Bacillus circulans strain 251 is a putative raw starch binding domain. Analysis of the maltose-dependent CGTase crystal structure revealed that each enzyme molecule contained three maltose molecules, situated at contact points between protein molecules. Two of these maltoses were bound to specific sites in the E-domain, the third maltose was bound at the C-domain. To delineate the roles in raw starch binding and cyclization reaction kinetics of the two maltose binding sites in the E-domain, we replaced Trp-616 and Trp-662 of maltose binding site 1 and Tyr-633 of maltose binding site 2 by alanines using site-directed mutagenesis. Purified mutant CGTases were characterized with respect to raw starch binding and cyclization reaction kinetics on both soluble and raw starch. The results show that maltose binding site 1 is most important for raw starch binding, whereas maltose binding site 2 is involved in guiding linear starch chains into the active site. beta-Cyclodextrin causes product inhibition by interfering with catalysis in the active site and the function of maltose binding site 2 in the E-domain. CGTase mutants in the E-domain maltose binding site 1 could no longer be crystallized as maltose-dependent monomers. Instead, the W616A mutant CGTase protein was successfully crystallized as a carbohydrate-independent dimer; its structure has been refined to 2.2 A resolution. The three-dimensional structure shows that, within the error limits, neither the absence of carbohydrates nor the W616A mutation caused significant further conformational changes. The modified starch binding and cyclization kinetic properties observed with the mutant CGTase proteins thus can be directly related to the amino acid replacements.


    Related Citations: 
    • Nucleotide Sequence and X-Ray Structure of Cyclodextrin Glycosyltransferase from Bacillus Circulans Strain 251 in a Maltose-Dependent Crystal Form
      Lawson, C.L.,Van Montfort, R.,Strokopytov, B.,Rozeboom, H.J.,Kalk, K.H.,De Vries, G.E.,Penninga, D.,Dijkhuizen, L.,Dijkstra, B.W.
      (1994) J.Mol.Biol. 236: 590
    • Maltodextrin-Dependent Crystallization of Cyclomaltodextrin Glucanotransferase from Bacillus Circulans
      Lawson, C.L.,Bergsma, J.,Bruinenberg, P.M.,De Vries, G.,Dijkhuizen, L.,Dijkstra, B.W.
      (1990) J.Mol.Biol. 214: 807


    Organizational Affiliation

    Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands. L.Dijkhuizen@biol.rug.nl




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CYCLODEXTRIN GLYCOSYLTRANSFERASE
A, B
686Bacillus circulansMutation(s): 1 
Gene Names: cgt
EC: 2.4.1.19
Find proteins for P43379 (Bacillus circulans)
Go to UniProtKB:  P43379
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.193 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 73.700α = 90.00
b = 84.800β = 107.00
c = 118.300γ = 90.00
Software Package:
Software NamePurpose
TNTrefinement
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-04-21
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance