>TIGR01369 CPSaseII_lrg carbamoyl-phosphate synthase, large subunit; InterPro: IPR006275 Carbamoyl phosphate synthase (CPSase) is a heterodimeric enzyme composed of a small and a large subunit (with the exception of CPSase III, see below). CPSase catalyses the synthesis of carbamoyl phosphate from biocarbonate, ATP and glutamine (6.3.5.5 from EC) or ammonia (6.3.4.16 from EC), and represents the first committed step in pyrimidine and arginine biosynthesis in prokaryotes and eukaryotes, and in the urea cycle in most terrestrial vertebrates , . CPSase has three active sites, one in the small subunit and two in the large subunit. The small subunit contains the glutamine binding site and catalyses the hydrolysis of glutamine to glutamate and ammonia. The large subunit has two homologous carboxy phosphate domains, both of which have ATP-binding sites; however, the N-terminal carboxy phosphate domain catalyses the phosphorylation of biocarbonate, while the C-terminal domain catalyses the phosphorylation of the carbamate intermediate . The carboxy phosphate domain found duplicated in the large subunit of CPSase is also present as a single copy in the biotin-dependent enzymes acetyl-CoA carboxylase (6.4.1.2 from EC) (ACC), propionyl-CoA carboxylase (6.4.1.3 from EC) (PCCase), pyruvate carboxylase (6.4.1.1 from EC) (PC) and urea carboxylase (6.3.4.6 from EC). Most prokaryotes carry one form of CPSase that participates in both arginine and pyrimidine biosynthesis, however certain bacteria can have separate forms. The large subunit in bacterial CPSase has four structural domains: the carboxy phosphate domain 1, the oligomerisation domain, the carbamoyl phosphate domain 2 and the allosteric domain . CPSase heterodimers from Escherichia coli contain two molecular tunnels: an ammonia tunnel and a carbamate tunnel. These inter-domain tunnels connect the three distinct active sites, and function as conduits for the transport of unstable reaction intermediates (ammonia and carbamate) between successive active sites . The catalytic mechanism of CPSase involves the diffusion of carbamate through the interior of the enzyme from the site of synthesis within the N-terminal domain of the large subunit to the site of phosphorylation within the C-terminal domain. Eukaryotes have two distinct forms of CPSase: a mitochondrial enzyme (CPSase I) that participates in both arginine biosynthesis and the urea cycle; and a cytosolic enzyme (CPSase II) involved in pyrimidine biosynthesis. CPSase II occurs as part of a multi-enzyme complex along with aspartate transcarbamoylase and dihydroorotase; this complex is referred to as the CAD protein . The hepatic expression of CPSase is transcriptionally regulated by glucocorticoids and/or cAMP . There is a third form of the enzyme, CPSase III, found in fish, which uses glutamine as a nitrogen source instead of ammonia . CPSase III is closely related to CPSase I, and is composed of a single polypeptide that may have arisen from gene fusion of the glutaminase and synthetase domains . This entry represents glutamine-dependent CPSase (6.3.5.5 from EC) from prokaryotes and eukaryotes (CPSase II). ; GO: 0004086 carbamoyl-phosphate synthase activity, 0006807 nitrogen compound metabolic process.

Probab=99.98 E-value=8.5e-31 Score=227.22 Aligned_cols=320 Identities=15% Similarity=0.172 Sum_probs=233.1 Q ss_pred CCCEEEEECCC-----H------HHHHHHHHHHHCCCEEEEEECCCCCC--HHHCCCEEEECCCCCHHHHHHHH--HHCC Q ss_conf 88789998098-----9------89999999988797899996767771--34226827987899999999997--4199 Q gi|254780158|r 2 KKKTIGIIGGG-----Q------LARMLSMSAARLGFCTVILDPDSNCP--ANQVSNQQIAARHDDIKALNTFA--DICD 66 (354) Q Consensus 2 ~~k~IgIlG~G-----q------L~rml~~aA~~lG~~v~v~d~~~~~p--a~~~ad~~~~~~~~D~~~l~~~~--~~~D 66 (354) T Consensus 5 ~i~kvLviGSGPi~IGQAaEFDYSGsQAcKALkEEGy~viLVNsNpATimTD~~~AD~vY~ePl-T~e~V~~IIEKERPD 83 (1089) T TIGR01369 5 DIKKVLVIGSGPIVIGQAAEFDYSGSQACKALKEEGYEVILVNSNPATIMTDPEMADKVYIEPL-TPEAVEKIIEKERPD 83 (1089) T ss_pred CCCEEEEECCCCCCHHHHCCCHHHHHHHHHHHHHCCCEEEEECCCCCCCCCCHHHCCCCCCCCC-CHHHHHHHHHHCCCC T ss_conf 8878999666731131202302478999999876495799975884723388668660025254-588886665316866 Q ss_pred EEEECCCC-CCHHHHH------HHHH-CCCCC-CCHHHHHHHHCCHHHHHHHHHCCCCCCCCCCCCHHHHHHHHHHCCCC Q ss_conf 99987722-2113334------4430-20034-87677876315278888876505886743210006888864100131 Q gi|254780158|r 67 YATYESEN-IPEKSIS------YLST-LLPTY-PSSRAIEISQDRLYEKKFFQESGLTTVDFYEINSQESLTNILGGFKG 137 (354) Q Consensus 67 vit~E~E~-i~~~~l~------~l~~-~~~v~-P~~~al~~~~dK~~~K~~l~~~gipt~~~~~v~s~~el~~~~~~~g~ 137 (354) T Consensus 84 giL~t~GGQTALNlav~L~~~GVL~kYgV~vLGT~~eaI~kaEDRe~F~~~M~ei~~pvp~S~~~~~~eEA~~~a~~~Gy 163 (1089) T TIGR01369 84 GILPTLGGQTALNLAVELEESGVLEKYGVEVLGTPVEAIKKAEDRELFREAMKEIGEPVPKSEIVHSVEEALKAAKEIGY 163 (1089) T ss_pred CHHCCCCCHHHHHHHHHHHHCCCCHHHCCEEECCCHHHHHHHCCHHHHHHHHHHCCCCCCCCCCCCCHHHHHHHHHHCCC T ss_conf 00025760357777886620685145291785234243520202799999999738998811002788999999962689 Q ss_pred EEEEECC-CCCCCCCCCCCCCCHHHHHHHHHHC----CCCCEEHHHCCCCCCCCCCEECCCCCCCEEEEECCCCC----- Q ss_conf 2554023-4675556645446746778987513----55501011114564433201014665413997053345----- Q gi|254780158|r 138 KGILKTR-RLGYDGKGQKVYHENDCTQNLYASL----GNVPLILERFTDFNCEISIIAARSLNGSICFYDPIQNT----- 207 (354) Q Consensus 138 P~vlKp~-~~GydGkG~~~i~~~~~l~~~~~~~----~~~~~iiEe~I~~~~Eisviv~r~~~G~~~~~p~~en~----- 207 (354) T Consensus 164 PviVRpAftLG--G~GgGiA~n~eEL~~~~~~aL~~SpI~qvL~EkSl~GWKE~EYEVmRD~~dNCItVCNmEN~DPmGV 241 (1089) T TIGR01369 164 PVIVRPAFTLG--GTGGGIASNEEELKEIVERALSASPINQVLVEKSLAGWKEIEYEVMRDSKDNCITVCNMENFDPMGV 241 (1089) T ss_pred CEEECCCHHCC--CCCCCEECCHHHHHHHHHHHHHHCCCCEEEEEEECCCCEEEEEEEEEECCCCEEEEECCCCCCCCCE T ss_conf 68981003238--8998522577899999998863088855750110033178898898626878899974547689845 Q ss_pred CC-CCCEEEEEECCC-CCHHHHHHHHHHHHHHHHHCCCCCC-CCCEEEECCC-CEEEEEEECCCCCCCEEEEHHHCCCCH Q ss_conf 43-555058985278-7878999999998867754024677-5310455388-408999412570456046210013588 Q gi|254780158|r 208 HV-NGILHKSIVPAS-ISQKTSLLAHSAMRKVLETLDYVGI-LCIEFFVTND-GNVIANEMAPRVHNSGHWTEASCVISQ 283 (354) Q Consensus 208 ~~-~gil~~s~~Pa~-i~~~~~~~a~~~a~~i~~~L~~~Gv-~~VEffv~~d-g~i~vnEiaPR~Hnsgh~t~~~~~~sq 283 (354) T Consensus 242 HTGdSI---VVAPSQTLtD~EYQ~LR~~sikIIR~lGi~GgGCNvQFAL~P~s~~Y~vIEvNPRvSRSS------ALAS- 311 (1089) T TIGR01369 242 HTGDSI---VVAPSQTLTDKEYQMLRDASIKIIRELGIVGGGCNVQFALDPDSGRYYVIEVNPRVSRSS------ALAS- 311 (1089) T ss_pred EECCCE---EECCCCCCCCHHHHHHHHHHHHHHHHCCCEECCCCEEEEECCCCCCEEEEEECCCCCHHH------HHHH- T ss_conf 707833---650763688078999999999999873912167421321507897069998678821358------9876- Q ss_pred HHHHHHHHHCCCCCCCHHC-C-----CEEEEEEECCC---CCCHHHH--HCCCCCEEEECCCCCCCCC Q ss_conf 9999999818899970004-8-----56799975577---0227889--7289968997088768979 Q gi|254780158|r 284 FEQHIRSITNLPLGNPNRH-S-----NCVMYNIIGSD---IDQYEQW--LHCDSSVIHIYGKSQTLCG 340 (354) Q Consensus 284 fe~h~rai~glpl~~~~~~-~-----~~~m~nilg~~---~~~~~~~--~~~~~~~~~~YgK~~~r~~ 340 (354) T Consensus 312 ------KATGYPiAkvAAKLAvGY~LdEl~N~vT~~T~A~FEPSLDYvVvKIPRW~f~KF~~v~r~LG 373 (1089) T TIGR01369 312 ------KATGYPIAKVAAKLAVGYGLDELKNPVTKTTPASFEPSLDYVVVKIPRWDFDKFEGVDRKLG 373 (1089) T ss_pred ------HHHCCHHHHHHHHHHCCCCCCCCCCCCCCCCCCCCCCCCCEEEECCCCCCCHHHCCCCCCCC T ss_conf ------65166289999998468878765688888535410467480886067887221057885415

HHsearch alignment for GI: 254780158 and conserved domain: TIGR01369