1DGR

Refined crystal structure of canavalin from jack bean


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.180 

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This is version 1.2 of the entry. See complete history

Literature

X-ray diffraction and atomic force microscopy analysis of twinned crystals: rhombohedral canavalin.

Ko, T.P.Kuznetsov, Y.G.Malkin, A.J.Day, J.McPherson, A.

(2001) Acta Crystallogr.,Sect.D 57: 829-839

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The structure of canavalin, the vicilin-class storage protein from jack bean, was refined to 1.7 A resolution in a highly twinned rhombohedral crystal of space group R3 and unit-cell parameters a = b = c = 83.0 A, alpha = beta = gamma = 111.1 degrees ...

    The structure of canavalin, the vicilin-class storage protein from jack bean, was refined to 1.7 A resolution in a highly twinned rhombohedral crystal of space group R3 and unit-cell parameters a = b = c = 83.0 A, alpha = beta = gamma = 111.1 degrees. The resulting R and R(free) were 0.176 and 0.245, respectively. The orthorhombic crystal structure (space group C222(1), unit-cell parameters a = 136.5, b = 150.3, c = 133.4 A) was also refined with threefold non-crystallographic symmetry restraints. R and R(free) were 0.181 and 0.226, respectively, for 2.6 A resolution data. No significant difference in the protein structure was seen between these two crystal forms, nor between these two and the hexagonal and cubic crystal forms reported elsewhere [Ko et al. (1993), Acta Cryst. D49, 478-489; Ko et al. (1993), Plant Physiol. 101, 729-744]. A phosphate ion was identified in the lumen of the C-terminal beta-barrel. Lattice interactions showed that the trimeric molecule could be well accommodated in both 'top-up' and 'bottom-up' orientations in a rhombohedral unit cell of the R3 crystal and explained the presence of a high twin fraction. The large inter-trimer stacking interface of the C222(1) crystal may account for its relative stability. Atomic force microscopy (AFM) investigations of the growth of three crystal forms of canavalin indicate the rhombohedral form to be unique. Unlike the other two crystal forms, it contains at least an order of magnitude more screw dislocations and stacking faults than any other macromolecular crystal yet studied, and it alone grows principally by generation of steps from the screw dislocations. The unusually high occurrence of the screw dislocations and stacking faults is attributed to mechanical stress produced by the alternate molecular orientations in the rhombohedral crystals and their organization into discrete domains or blocks. At boundaries of alternate domains, lattice strain is relieved by the formation of the screw dislocations.


    Related Citations: 
    • Determination of three crystal structures of canavalin by molecular replacement
      Ko, T.-P.,Ng, J.D.,Day, J.,Greenwood, A.,McPherson, A.
      (1993) Acta Crystallogr.,Sect.D 49: 478


    Organizational Affiliation

    Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CANAVALIN
A, B, C
178Canavalia ensiformisMutation(s): 0 
Find proteins for P50477 (Canavalia ensiformis)
Go to UniProtKB:  P50477
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
CANAVALIN
X, V, N
79Canavalia ensiformisMutation(s): 0 
Find proteins for P50477 (Canavalia ensiformis)
Go to UniProtKB:  P50477
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
CANAVALIN
Y, W, M
93Canavalia ensiformisMutation(s): 0 
Find proteins for P50477 (Canavalia ensiformis)
Go to UniProtKB:  P50477
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
N, V, X
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.180 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 136.500α = 90.00
b = 150.300β = 90.00
c = 133.400γ = 90.00
Software Package:
Software NamePurpose
MERLOTphasing
SDMSdata scaling
CNSrefinement
SDMSdata collection
SDMSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-12-29
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance