1GPT

SOLUTION STRUCTURE OF GAMMA 1-H AND GAMMA 1-P THIONINS FROM BARLEY AND WHEAT ENDOSPERM DETERMINED BY 1H-NMR: A STRUCTURAL MOTIF COMMON TO TOXIC ARTHROPOD PROTEINS

Summary for 1GPT

• Entry DOI: 10.2210/pdb1gpt/pdb
• Descriptor: GAMMA-1-H THIONIN (1 entity in total)
• Functional Keywords: plant toxin
• Biological source: Hordeum vulgare
• Total number of polymer chains: 1
• Total formula weight: 5261.27

Authors

Bruix, M.,Jimenez, M.A.,Santoro, J.,Gonzalez, C.,Colilla, F.J.,Mendez, E.,Rico, M. (deposition date: 1992-07-29, release date: 1993-10-31, Last modification date: 2024-10-23)

Primary citation

Bruix, M.,Jimenez, M.A.,Santoro, J.,Gonzalez, C.,Colilla, F.J.,Mendez, E.,Rico, M.
Solution structure of gamma 1-H and gamma 1-P thionins from barley and wheat endosperm determined by 1H-NMR: a structural motif common to toxic arthropod proteins.
Biochemistry, 32:715-724, 1993

PubMed Abstract: The complete assignment of the proton NMR spectra of the homologous gamma 1-hordothionin and gamma 1-purothionin (47 amino acids, 4 disulfide bridges) from barley and wheat, respectively, has been performed by two-dimensional sequence-specific methods. A total of 299 proton-proton distance constraints for gamma 1-H and 285 for gamma 1-P derived from NOESY spectra have been used to calculate the three-dimensional solution structures. Initial structures have been generated by distance geometry methods and further refined by dynamical simulated annealing calculations. Both proteins show identical secondary and tertiary structure with a well-defined triple-stranded antiparallel beta-sheet (residues 1-6, 31-34, and 39-47), an alpha-helix (residues 16-28), and the corresponding connecting loops. Three disulfide bridges are located in the hydrophobic core holding together the alpha-helix and the beta-sheet and forming a cysteine-stabilized alpha-helical (CSH) motif. Moreover, a clustering of positive charges is observed on the face of the beta-sheet opposite to the helix. The three-dimensional structures of the gamma-thionins differ remarkably from plant alpha- and beta-thionins and crambin. However, they show a higher structural analogy with scorpion toxins and insect defensins which also present the CSH motif.

PubMed: 8380707
DOI: 10.1021/bi00053a041

Experimental method

SOLUTION NMR