Carbamoyl phosphate synthetase (glutamine-hydrolysing) () is an enzyme that catalyzes the reactions that produce

carbamoyl phosphate Carbamoyl phosphate is an anion of biochemical significance. In land-dwelling animals, it is an intermediary metabolite in nitrogen disposal through the urea cycle and the synthesis of pyrimidines. Its enzymatic counterpart, carbamoyl phosphate syn ...

in the

cytosol The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondri ...

(as opposed to type I, which functions in the mitochondria). Its systemic name is ''hydrogen-carbonate:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)''. In

pyrimidine Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The othe ...

biosynthesis, it serves as the rate-limiting enzyme and catalyzes the following reaction: : 2 ATP + L-

glutamine Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral ...

+ HCO₃⁻ + H₂O

\rightleftharpoons

2 ADP +

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosph ...

+ L-

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

(overall reaction) : (1a) L-glutamine + H₂O

\rightleftharpoons

L-glutamate + NH₃ : (1b) 2 ATP + HCO₃⁻ + NH₃

\rightleftharpoons

2 ADP + phosphate + carbamoyl phosphate It is activated by

ATP ATP may refer to: Companies and organizations * Association of Tennis Professionals, men's professional tennis governing body * American Technical Publishers, employee-owned publishing company * ', a Danish pension * Armenia Tree Project, non ...

and

PRPP Phosphoribosyl pyrophosphate (PRPP) is a pentose phosphate. It is a biochemical intermediate in the formation of purine nucleotides via inosine-5-monophosphate, as well as in pyrimidine nucleotide formation. Hence it is a building block for DNA ...

and it is inhibited by UMP (

Uridine monophosphate Uridine monophosphate (UMP), also known as 5′-uridylic acid (conjugate base uridylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside uridine. UMP consists of the phosphate group, the pe ...

, the end product of the pyrimidine synthesis pathway). Neither CPSI nor CPSII require biotin as a coenzyme, as seen with most carboxylation reactions. It is one of the three enzyme functions coded by the

CAD Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve c ...

gene. It is classified under .

References

External links

* EC 6.3.5 {{6.3-enzyme-stub

See also

References

External links