Comparing the modeled structures of PR-4 proteins from wheat.
We have constructed three-dimensional models of four pathogenesis-related (PR) proteins from wheat (wheatwins) belonging to the PR-4 family. All the models were based on the knowledge of the tertiary structure of barwin, a highly homologous protein from barley. Wheatwin1 and wheatwin2 differ in two amino acid residues (positions 62 and 68) out of 125. Wheatwin4 differs from wheatwin2 in one residue at position 78, while wheatwin3 differs from wheatwin1 in one residue at position 88. The global folding and the secondary structures were very similar through all the sequences, including the regions of the amino acid substitutions. The main differences were found in the traits 15-21, 84-86 and 91-93. Trait 15-21 was predicted as ss-sheet in wheatwin4 and random-coil in the other proteins. Trait 84-86 was predicted as ss-sheet in wheatwin3 and random-coil in the other proteins. Trait 91-93 was predicted as random coil in wheatwin1 and wheatwin3 and ss-sheet in the other two proteins. Traits 15-21 and 84-86 were exposed, while trait 91-93 was quite hidden in all the proteins. The antifungal activities of the four proteins towards the specific pathogenic fungus Fusarium culmorum were distinct and well correlated to the structural differences. These results suggest that these regions may have a role in the action mechanism, which is still unknown.
Caporale
Carlo
C
Dipartimento di Agrobiologia ed Agrochimica, Università della Tuscia, Via S. Camillo de Lellis, 01100 Viterbo, Italy. caporale@unitus.it
Facchiano
Angelo
A
Bertini
Laura
L
Leonardi
Luca
L
Chilosi
Gabriele
G
Buonocore
Vincenzo
V
Caruso
Carla
C
D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005670:Fusarium / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D006860:Hydrogen Bonding; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D011487:Protein Conformation; D017510:Protein Folding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D014908:Triticum / Q000737:chemistry* / Q000235:genetics
D000890:Anti-Infective Agents; D010940:Plant Proteins; D020033:Protein Isoforms; C062880:Win-1 proteins, plant; C053376:pathogenesis-related proteins, plant