May be involved in fertilization (By similarity). Has no detectable bacteriolytic and lysozyme activities in vitro (By similarity). Monomer. Found in the principal piece of sperm tail. Belongs to the glycosyl hydrolase 22 family. Although it belongs to the glycosyl hydrolase 22 family, Gly-72 is present instead of the conserved Asp which is an active site residue. It is therefore expected that this protein lacks hydrolase activity.