ChEBI: D-alanyl-D-alanine is a dipeptide comprising D-alanine with a D-alanyl residue attached to the alpha-nitrogen. It is a component of bacterial peptidoglycan and forms an important target for development of antibacterial drugs. It has a role as an Escherichia coli metabolite. It is a tautomer of a D-alanyl-D-alanine zwitterion.