Carnosine Synthase 1 (CARNS1)

CARNS1, a member of the ATP-grasp family of ATPases, catalyzes the formation of carnosine and homocarnosine, which are found mainly in skeletal muscle and the central nervous system, respectively. The deduced proteins contain 957 and 950 amino acids, respectively, and both contain 2 ATP-grasp domains, with highest conservation in the C-terminal catalytic domain. Gel filtration analysis showed that mouse Atpgd1, like the chicken enzyme, was expressed as a homotetramer of about 430 kD in transfected HEK293 cells.Mouse and human ATPGD1 catalyzed the same reaction following expression in HEK293 cells. All 3 enzymes were not specific with respect to the amino acid serving as the acceptor, although L-histidine was preferred, and all 3 were also more efficient in synthesizing carnosine than homocarnosine and other dipeptides.