1H NMR structure of an antifungal gamma-thionin protein SIalpha1: similarity to scorpion toxins.
The three-dimensional structure of the Sorghum bicolor seed protein gamma-thionin SIalpha1 has been determined by 2D 1H nuclear magnetic resonance (NMR) spectroscopy. The secondary structure of this 47-residue antifungal protein with four disulphide bridges consists of a three-stranded antiparallel sheet and one helix. The helix is tethered to the sheet by two disulphide bridges which link two successive turns of the helix to alternate residues i, i+2 in one strand. Possible binding sites for antifungal activity are discussed. The same fold has been observed previously in several scorpion toxins.
Department of Biochemistry and Molecular Biology, University College, London, United Kingdom.
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C
Bloch
S U
SU
Patel
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Baud
M J
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Zvelebil
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Carr
P J
PJ
Sadler
J M
JM
Thornton
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry*; D023181:Antimicrobial Cationic Peptides; D029681:Arabidopsis Proteins; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry*; D006109:Poaceae / Q000737:chemistry; D012604:Scorpion Venoms / Q000737:chemistry*
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D029681:Arabidopsis Proteins; D010940:Plant Proteins; D012604:Scorpion Venoms; C097482:THI2.1 protein, Arabidopsis