Catalyzes hydrolysis of the D-alanyl-D-alanine dipeptide. May play a role in immunity or defense against glycopeptide antibiotics (perhaps at a moderate level) in the soil environment. Might confer vancomycin resistance to S.coelicolor. D-alanyl-D-alanine + H2O = 2 D-alanine Binds 1 zinc ion per subunit. Belongs to the peptidase M15D family.