Carbamoyl phosphate synthase II

Carbamoyl phosphate synthetase (glutamine-hydrolysing) (<a href="/facts/Enzyme_Commission_number/Y5GNLRKX">EC</a> <a href="https://www.enzyme-database.org/query.php?ec=6.3.5.5">6.3.5.5</a>) is an enzyme that catalyzes the reactions that produce <a href="/facts/Carbamoyl_phosphate/tTLwfema">carbamoyl phosphate</a> in the <a href="/facts/Cytosol/VyXgygWm">cytosol</a> (as opposed to type I, which functions in the <a href="/facts/Mitochondria/ErHqrdJ1">mitochondria</a>). Its systemic name is hydrogen-carbonate:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating).
In <a href="/facts/Pyrimidine/uFRSB8Cq">pyrimidine</a> biosynthesis, it serves as the rate-limiting enzyme and catalyzes the following reaction:

2 ATP + L-<a href="/facts/Glutamine/t94zX4SK">glutamine</a> + HCO3− + H2O 
 
 
 
 ⇌
 
 
 {\displaystyle \rightleftharpoons }
 
 2 ADP + <a href="/facts/Phosphate/FDGVCxUG">phosphate</a> + L-<a href="/facts/Glutamate/7oXbNcvu">glutamate</a> + <a href="/facts/Carbamoyl_phosphate/tTLwfema">carbamoyl phosphate</a> (overall reaction)
(1a) L-glutamine + H2O 
 
 
 
 ⇌
 
 
 {\displaystyle \rightleftharpoons }
 
 L-glutamate + NH3
(1b) 2 ATP + HCO3− + NH3 
 
 
 
 ⇌
 
 
 {\displaystyle \rightleftharpoons }
 
 2 ADP + phosphate + carbamoyl phosphate
It is activated by <a href="/facts/Adenosine_triphosphate/nB9bwgcU">ATP</a> and <a href="/facts/PRPP/Fjnq3y18">PRPP</a> and it is inhibited by UTP (Uridine triphosphate)
Neither CPSI nor CPSII require <a href="/facts/Biotin/WAaVxyB7">biotin</a> as a coenzyme, as seen with most carboxylation reactions.
It is one of the four functional enzymatic domains coded by the <a href="/facts/CAD_(gene)/WlC46vvR">CAD</a> gene. The CAD gene is a large gene. It uses a single strand to code for these enzyme jobs. It is classified under <a href="/facts/Enzyme_Commission_number/Y5GNLRKX">EC</a> <a href="https://enzyme.expasy.org/EC/6.3.5.5">6.3.5.5</a>.

Carbamoyl phosphate synthase II open-in-new

Carbamoyl phosphate synthase II