CARNS1 (EC 6.3.2.11), a member of the ATP-grasp family of ATPases, catalyzes the formation of carnosine (beta-alanyl-L-histidine) and homocarnosine (gamma-aminobutyryl-L-histidine), which are found mainly in skeletal muscle and the central nervous system, respectively (Drozak et al., 2010 [PubMed 20097752]).