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.
Bloch
C
C
Department of Biochemistry and Molecular Biology, University College, London, United Kingdom.
Patel
S U
SU
Baud
F
F
Zvelebil
M J
MJ
Carr
M D
MD
Sadler
P J
PJ
Thornton
J M
JM
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