Zinc-dependent metalloprotease, astacin_like subfamily or peptidase family M12A, a group of zinc-dependent proteolytic enzymes with a HExxH zinc-binding site/active site. Members of this family may have an amino terminal propeptide, which is cleaved to yield the active protease domain, which is consequently always found at the N-terminus in multi-domain architectures. This family includes: astacin, a digestive enzyme from Crayfish; meprin, a multiple domain membrane component that is constructed from a homologous alpha and beta chain, proteins involved in (bone) morphogenesis, tolloid from drosophila, and the sea urchin SPAN protein, which may also play a role in development.