This family of proteins is residues 218-289 of Het-s, a protein of Podospora anserina. Het-s plays a role in heterokaryon incompatibility which prevents different forms of parasitism [1]. This region of the protein is the C-terminal end and is unstructured in solution but forms infectious fibrils in vitro which has a structure consisting of a left-handed beta solenoid which contains two windings per molecule [1].

1: Amyloid fibrils of the HET-s(218-289) prion form a beta solenoid with a triangular hydrophobic core. Wasmer C, Lange A, Van Melckebeke H, Siemer AB, Riek R, Meier BH; Science. 2008;319:1523-1526. PMID:18339938