1CNV

CRYSTAL STRUCTURE OF CONCANAVALIN B AT 1.65 A RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 

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This is version 1.2 of the entry. See complete history


Literature

Crystal structure of concanavalin B at 1.65 A resolution. An "inactivated" chitinase from seeds of Canavalia ensiformis.

Hennig, M.Jansonius, J.N.Terwisscha van Scheltinga, A.C.Dijkstra, B.W.Schlesier, B.

(1995) J Mol Biol 254: 237-246

  • DOI: 10.1006/jmbi.1995.0614
  • Primary Citation of Related Structures:  
    1CNV

  • PubMed Abstract: 
  • Seeds of Canavalia ensiformis (jack bean) contain besides large amounts of canavalin and concanavalin A, a protein with a molecular mass of 33,800 which has been named concanavalin B. Although concanavalin B shares about 40% sequence identity with pl ...

    Seeds of Canavalia ensiformis (jack bean) contain besides large amounts of canavalin and concanavalin A, a protein with a molecular mass of 33,800 which has been named concanavalin B. Although concanavalin B shares about 40% sequence identity with plant chitinases belonging to glycosyl hydrolase family 18, no chitinase activity could be detected for this protein. To resolve this incongruity concanavalin B was crystallised and its three-dimensional structure determined at 1.65 A (1 A = 0.1 nm) resolution. The structure consists of a single domain with a (beta/alpha)8 topology. A 30 amino acid residue long loop occurs between the second beta-strand of the barrel and the second alpha-helix. This extended loop is unusual for the (beta/alpha)8 topology, but appears in a similar conformation in the structures of the seed protein narbonin and several chitinases as well. Two non-proline cis-peptide bonds are present in the structure of concanavalin B: Ser34-Phe, and Trp265-Asn. This structural feature is rarely observed in proteins, but could also be identified in the three-dimensional structures of family 18 chitinases and narbonin in coincident positions. In the chitinases the aromatic residues of the non-proline cis-peptides have been proposed to have a function in the binding of the substrate. The region in concanavalin B, where in chitinases the active site is located, shows two significant differences. First, the catalytic glutamic acid is a glutamine in concanavalin B. Second, although part of the substrate binding cleft of the chitinases is present in concanavalin B, it is much shorter. From this we conclude that concanavalin B and family 18 chitinases are closely related, but that concanavalin B has lost its enzymatic function. It still may act as a carbohydrate binding protein, however.


    Related Citations: 
    • Sequence Analysis of Concanavalin B from Canavalia Ensiformis Reveals Homology to Chitinases
      Schlesier, B., Nong, V.H., Horstmann, C.H., Hennig, M.
      () To be published --: --

    Organizational Affiliation

    Department of Structural Biology, University of Basel, Switzerland.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CONCANAVALIN BA299Canavalia ensiformisMutation(s): 0 
Find proteins for P49347 (Canavalia ensiformis)
Explore P49347 
Go to UniProtKB:  P49347
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.4α = 90
b = 81.4β = 90
c = 102.2γ = 120
Software Package:
Software NamePurpose
XDSdata scaling
X-PLORmodel building
X-PLORrefinement
XDSdata reduction
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 1995-02-20 
  • Released Date: 1996-03-08 
  • Deposition Author(s): Hennig, M.

Revision History 

  • Version 1.0: 1996-03-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance