This family represents a conserved region approximately 150 residues long within various heterokaryon incompatibility proteins that seem to be restricted to ascomycete fungi. Genetic differences in specific het genes prevent a viable heterokaryotic fungal cell from being formed by the fusion of filaments from two different wild-type strains [1]. Many family members also contain the Pfam:PF00400 repeat and the Pfam:PF05729 domain.

1: HET-E and HET-D belong to a new subfamily of WD40 proteins involved in vegetative incompatibility specificity in the fungus Podospora anserina. Espagne E, Balhadere P, Penin ML, Barreau C, Turcq B; Genetics 2002;161:71-81. PMID:12019224