1XD5

Crystal structures of novel monomeric monocot mannose-binding lectins from Gastrodia elata


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Mechanism Governing the Quaternary Organization of Monocot Mannose-binding Lectin Revealed by the Novel Monomeric Structure of an Orchid Lectin

Liu, W.Yang, N.Ding, J.Huang, R.H.Hu, Z.Wang, D.C.

(2005) J Biol Chem 280: 14865-14876

  • DOI: 10.1074/jbc.M411634200
  • Primary Citation of Related Structures:  
    1XD6, 1XD5

  • PubMed Abstract: 
  • Two isoforms of an antifungal protein, gastrodianin, were isolated from two subspecies of the orchid Gastrodia elata, belonging to the protein superfamily of monocot mannose-specific lectins. In the context that all available structures in this superfamily are oligomers so far, the crystal structures of the orchid lectins, both at 2 ...

    Two isoforms of an antifungal protein, gastrodianin, were isolated from two subspecies of the orchid Gastrodia elata, belonging to the protein superfamily of monocot mannose-specific lectins. In the context that all available structures in this superfamily are oligomers so far, the crystal structures of the orchid lectins, both at 2.0 A, revealed a novel monomeric structure. It resulted from the rearrangement of the C-terminal peptide inclusive of the 12th beta-strand, which changes from the "C-terminal exchange" into a "C-terminal self-assembly" mode. Thus, the overall tertiary scaffold is stabilized with an intramolecular beta-sheet instead of the hybrid observed on subunit/subunit interface in all known homologous dimeric or tetrameric lectins. In contrast to the constrained extended conformation with a cis peptide bond between residues 98 and 99 commonly occurring in oligomers, a beta-hairpin forms from position 97 to 101 with a normal trans peptide bond at the corresponding site in gastrodianin, which determines the topology of the C-terminal peptide and thereby its unique fold pattern. Sequence and structure comparison shows that residue replacement and insertion at the position where the beta-hairpin occurs in association with cis-trans inter-conversion of the specific peptide bond (97-98) are possibly responsible for such a radical structure switch between monomers and oligomers. Moreover, this seems to be a common melody controlling the quaternary states among bulb lectins through studies on sequence alignment. The observations revealed a structural mechanism by which the quaternary organization of monocot mannose binding lectins could be governed. The mutation experiment performed on maltose-binding protein-gastrodianin fusion protein followed by a few biochemical detections provides direct evidence to support this conclusion. Potential carbohydrate recognition sites and biological implications of the orchid lectin based on its monomeric state are also discussed in this paper.


    Organizational Affiliation

    Center for Structural and Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
antifungal protein GAFP-1A, B, C, D112Gastrodia elataMutation(s): 0 
UniProt
Find proteins for Q9AXZ2 (Gastrodia elata)
Explore Q9AXZ2 
Go to UniProtKB:  Q9AXZ2
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
E [auth A], F [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.087α = 90
b = 91.488β = 90
c = 81.132γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
CCP4data scaling
MOLREPphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-01-11
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance