Function
Carbamoyl phosphate synthetase (CPS) catalyzes the production of carbamoyl phosphate from ATP, Mg+2, bicarbonate and glutamine. CPS is part of the pyrimidine and arginine biosynthesis as well as the urea cycle in vertebrates. Ornithine is an allosteric effector of CPS.[1] There are 3 forms of CPS:
- CPS I participates in the urea cycle. CPS I uses glutamine for NH3 source.
- CPS II participates in pyrimidine metabolism
- CPS III is found in fish.
Disease
CPS I deficiency causes the accumulation of NH3 in the blood.
Structural highlights
CPS I and II are composed of 2 subunits. The large subunit contain active sites which bind nucleotides and other effectors. The small subunit catalyzes the hydrolysis of glutamine to glutamate and NH3. The .[2] CPS I contains a methylglyoxal synthetase (MGS) domain which binds . Water molecules are shown as red spheres.
.
.
.
3D structures of carbamoyl phosphate synthetase
Carbamoyl phosphate synthetase 3D structures