U合成CT Glutamine Glutamate ATP +H,0 ADP+P:+2 H HN CH N CH 0=C、CH CTP合成酶 0=C、CH Ribose triphosphate Ribose triphosphate Acivicin Uridine triphosphate Cytidine triphosphate (UTP Azaserine (CTPUTP合成CTP CTP合成酶 Acivicin Azaserine 