View source for Carbamoyl phosphate synthase II

{{Infobox enzyme
| Name = Carbamoyl-phosphate synthetase (glutamine-hydrolysing)
| EC_number = 6.3.5.5
| CAS_number = 37233-48-0
| IUBMB_EC_number = 6/3/5/5
| GO_code = 
| image = 
| width = 
| caption =
}}
{{protein
|Name=carbamoyl-phosphate synthetase 1, aspartate transcarbamylase, and dihydroorotase
|caption=
|image=
|width=
|HGNCid=1424
|Symbol=CAD
|AltSymbols=
|EntrezGene=790
|OMIM=114010
|RefSeq=NM_004341
|UniProt=P27708
|PDB=
|ECnumber=
|Chromosome=2
|Arm=p
|Band=21
|LocusSupplementaryData=
}}
'''Carbamoyl phosphate synthetase II''' ({{EC number|6.3.5.5}}) is an enzyme that catalyzes the reactions that produce [[carbamoyl phosphate]] in the [[cytosol]] (as opposed to type I, which functions in the [[mitochondria]]). Its systemic name is ''hydrogen-carbonate:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)''.<ref>{{cite journal | vauthors = Anderson PM, Meister A | title = Evidence for an activated form of carbon dioxide in the reaction catalyzed by Escherichia coli carbamyl phosphate synthetase | journal = Biochemistry | volume = 4 | issue = 12 | pages = 2803–9 | date = December 1965 | pmid = 5326356 | doi = 10.1021/bi00888a034 }}</ref><ref>{{cite journal | vauthors = Kalman SM, Duffield PH, Brzozowski T | title = Purification and properties of a bacterial carbamyl phosphate synthetase | journal = The Journal of Biological Chemistry | volume = 241 | issue = 8 | pages = 1871–7 | date = April 1966 | pmid = 5329589 }}</ref><ref>{{cite journal | vauthors = Yip MC, Knox WE | title = Glutamine-dependent carbamyl phosphate synthetase. Properties and distribution in normal and neoplastic rat tissues | journal = The Journal of Biological Chemistry | volume = 245 | issue = 9 | pages = 2199–204 | date = May 1970 | pmid = 5442268 }}</ref><ref>{{cite journal | vauthors = Stapleton MA, Javid-Majd F, Harmon MF, Hanks BA, Grahmann JL, Mullins LS, Raushel FM | title = Role of conserved residues within the carboxy phosphate domain of carbamoyl phosphate synthetase | journal = Biochemistry | volume = 35 | issue = 45 | pages = 14352–61 | date = November 1996 | pmid = 8916922 | doi = 10.1021/bi961183y }}</ref><ref>{{cite journal | vauthors = Holden HM, Thoden JB, Raushel FM | title = Carbamoyl phosphate synthetase: a tunnel runs through it | journal = Current Opinion in Structural Biology | volume = 8 | issue = 6 | pages = 679–85 | date = December 1998 | pmid = 9914247 | doi = 10.1016/s0959-440x(98)80086-9 }}</ref><ref>{{cite journal | vauthors = Raushel FM, Thoden JB, Reinhart GD, Holden HM | title = Carbamoyl phosphate synthetase: a crooked path from substrates to products | journal = Current Opinion in Chemical Biology | volume = 2 | issue = 5 | pages = 624–32 | date = October 1998 | pmid = 9818189 | doi = 10.1016/s1367-5931(98)80094-x }}</ref><ref>{{cite journal | vauthors = Raushel FM, Thoden JB, Holden HM | title = The amidotransferase family of enzymes: molecular machines for the production and delivery of ammonia | journal = Biochemistry | volume = 38 | issue = 25 | pages = 7891–9 | date = June 1999 | pmid = 10387030 | doi = 10.1021/bi990871p }}</ref><ref>{{cite journal | vauthors = Thoden JB, Huang X, Raushel FM, Holden HM | title = Carbamoyl-phosphate synthetase. Creation of an escape route for ammonia | journal = The Journal of Biological Chemistry | volume = 277 | issue = 42 | pages = 39722–7 | date = October 2002 | pmid = 12130656 | doi = 10.1074/jbc.M206915200 }}</ref>

In [[pyrimidine]] biosynthesis, it serves as the rate-limiting enzyme and catalyzes the following reaction:
: 2 ATP + L-[[glutamine]] + HCO<sub>3</sub><sup>−</sup> + H<sub>2</sub>O <math>\rightleftharpoons</math> 2 ADP + [[phosphate]] + L-[[glutamate]] + [[carbamoyl phosphate]] (overall reaction)
: (1a) L-glutamine + H<sub>2</sub>O <math>\rightleftharpoons</math> L-glutamate + NH<sub>3</sub>
: (1b) 2 ATP + HCO<sub>3</sub><sup>−</sup> + NH<sub>3</sub> <math>\rightleftharpoons</math> 2 ADP + phosphate + carbamoyl phosphate

It is activated by [[Adenosine triphosphate|ATP]] and [[PRPP]]<ref>{{cite web|url=https://www.inkling.com/read/illustrated-reviews-biochemistry-harvey-5th/chapter-22/pyrimidine-synthesis-and|title=Unsupported Browser|first=|last=Inkling|date=|website=Inkling|accessdate=25 April 2018}}</ref> and it is inhibited by UMP ([[Uridine monophosphate]], 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 (gene)|CAD]] gene. It is classified under {{EC number|6.3.5.5}}.

== Nomenclature ==

Carbamoyl-phosphate synthetase (glutamine-hydrolysing) is also known as:
* hydrogen-carbonate:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)
* carbamyl phosphate synthetase (glutamine)
* glutamine-dependent carbamyl phosphate synthetase
* [[carbamoyl phosphate synthetase]]
* CPS
* carbon-dioxide:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)
{{clear}}
== References ==
{{reflist|32em}}

== External links ==
* {{MeshName|Carbamoyl-Phosphate+Synthase+(Glutamine-Hydrolyzing)}}

{{Nucleotide metabolism}}
{{Multienzyme complexes}}
{{Ligases CO CS and CN}}
{{Enzymes}}
{{Portal bar|Molecular and Cellular Biology|border=no}}

{{6.3-enzyme-stub}}

[[Category:EC 6.3.5]]