Thionins are small proteins found solely in higher plants. Typically, a thionin consists of 45-48 amino acid residues. 6-8 of these are cysteines forming 3-4 disulfide bonds. α- and β-thionins are related to each other. The γ-thionins have a superficially similar structure but are an unrelated class of protein, now called plant defensins (AllFam:AF059). Thionins are toxic to animal cells, presumably attacking the cell membrane and rendering it permeable. They are mainly found in seeds where they may act as a defence against consumption by animals [1].
Alpha-purothionin from wheat was identified as a minor food allergen [2].
Family-defining Pfam domains (at least one of these domains is present in each family member):
| Pfam domain | Pfam clan | ||
| PF00321 | Plant thionin | - | |
If you have updates or corrections for this entry, please contact the site administrator: christian.radauer@meduniwien.ac.at .
