This family represents bacterial uncharacterised proteins such as Uncharacterized conserved protein Dip1984 from Corynebacterium diphtheriae, which shows an all-alpha structure. Some members of this family are annotated as septicolysin, such as Swiss:H6NMB2, a cholesterol-dependent pore-forming cytolysin that acts to facilitate the infection of certain pathogenic gram-positive bacteria.