Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 30 
  • Selection Criteria: target function 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Solution structure, backbone dynamics and chitin binding of the anti-fungal protein from Streptomyces tendae TU901.

Campos-Olivas, R.Horr, I.Bormann, C.Jung, G.Gronenborn, A.M.

(2001) J Mol Biol 308: 765-782

  • DOI: https://doi.org/10.1006/jmbi.2001.4622
  • Primary Citation of Related Structures:  
    1G6E, 1GH5

  • PubMed Abstract: 

    AFP1 is a recently discovered anti-fungal, chitin-binding protein from Streptomyces tendae Tü901. Mature AFP1 comprises 86 residues and exhibits limited sequence similarity to the cellulose-binding domains of bacterial cellulases and xylanases. No similarity to the Cys and Gly-rich domains of plant chitin-binding proteins (e.g. agglutinins, lectins, hevein) is observed. AFP1 is the first chitin-binding protein from a bacterium for which anti-fungal activity was shown. Here, we report the three-dimensional solution structure of AFP1, determined by nuclear magnetic resonance spectroscopy. The protein contains two antiparallel beta-sheets (five and four beta-strands each), that pack against each other in a parallel beta-sandwich. This type of architecture is conserved in the functionally related family II of cellulose-binding domains, albeit with different connectivity. A similar fold is also observed in other unrelated proteins (spore coat protein from Myxococcus xanthus, beta-B2 and gamma-B crystallins from Bos taurus, canavalin from Jack bean). AFP1 is therefore classified as a new member of the betagamma-crystallin superfamily. The dynamics of the protein was characterized by NMR using amide 15N relaxation and solvent exchange data. We demonstrate that the protein exhibits an axially symmetric (oblate-like) rotational diffusion tensor whose principal axis coincides to within 15 degrees with that of the inertial tensor. After completion of the present structure of AFP1, an identical fold was reported for a Streptomyces killer toxin-like protein. Based on sequence comparisons and clustering of conserved residues on the protein surface for different cellulose and chitin-binding proteins, we postulate a putative sugar-binding site for AFP1. The inability of the protein to bind short chitin fragments suggests that certain particular architectural features of the solid chitin surface are crucial for the interaction.

  • Organizational Affiliation

    Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ANTIFUNGAL PROTEIN87Streptomyces tendaeMutation(s): 0 
Gene Names: AFP
Find proteins for Q9RCK8 (Streptomyces tendae)
Explore Q9RCK8 
Go to UniProtKB:  Q9RCK8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9RCK8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 30 
  • Selection Criteria: target function 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-03-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-23
    Changes: Data collection, Database references, Derived calculations
  • Version 1.4: 2022-12-21
    Changes: Database references