>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=100.00 E-value=1.7e-37 Score=290.96 Aligned_cols=288 Identities=20% Similarity=0.391 Sum_probs=240.2 Q ss_pred EEEEECCC------HHH------HHHHHHHHHCCCCCEEEEECCCHHHH----HCCEEEECCCCCHHHHHHHHHHHCCCE Q ss_conf 58998865------889------99999998589967899954983575----117055128789899999998718979 Q gi|254780206|r 2 RVLLIGSG------GRE------HALAWKIAQSPLLSELWSIPGNPGIA----QHAQCVAIDIQNHSAIIHFCQEKHIDL 65 (424) Q Consensus 2 kILviGsG------grE------hAl~~~l~~s~~~~~v~~~pgN~g~~----~~~~~~~i~~~d~~~i~~~a~~~~iDl 65 (424) T Consensus 575 ~~lvlGSGp~RIGqgvEFDYc~Vh~-~~aLr~~Gy--e~ImiN~NPETVSTDyD~sDrLYFEplt~E~Vm~I~e~E~~~G 651 (1089) T TIGR01369 575 KVLVLGSGPNRIGQGVEFDYCCVHA-VLALREAGY--ETIMINYNPETVSTDYDTSDRLYFEPLTFEDVMNIIELEKPEG 651 (1089) T ss_pred EEEEECCCCEECCCCEEEHHHHHHH-HHHHHHCCC--EEEEEECCCCCCCCCHHHHHHCCCCCCCCCCCEEHEEECCCCE T ss_conf 6899878451406631205678999-999987299--5999977899743666651011587635031001100058667 Q ss_pred EEE--CCCHHHHHHHHHHHHHCC-CCEEECCHHHHH-HHHCCHHHHHHHHHHHHHCCCCCCCCCCHHHHHHHHCCCCEEE Q ss_conf 999--795578748998986058-806701066655-5201023578887653101111223440111112101242025 Q gi|254780206|r 66 VVV--GPELPLVNGISDALNAAG-FKVFGPSQRAAK-LESSKSFAKKFCTKYGIPTATYQHFSDPMKAKQYVQNKSMPIV 141 (424) Q Consensus 66 viv--gpE~pL~~gi~d~l~~~g-i~v~Gp~~~aa~-le~sK~~~K~~l~~~gIPt~~~~~~~~~~ea~~~~~~~g~PvV 141 (424) T Consensus 652 VIVq~GGQtp~--nlA~~L~~~GG~~iLGTS~~~ID~AEDR~kF-s~~l~~Lgi~QP~~~~a~s~eea~~~A~~iGYPvl 728 (1089) T TIGR01369 652 VIVQFGGQTPL--NLAKELEEAGGVPILGTSPESIDRAEDREKF-SELLDELGIPQPEWKIATSVEEAKEFASEIGYPVL 728 (1089) T ss_pred EEEECCCHHHH--HHHHHHHHCCCCEEECCCHHHHHHHCCHHHH-HHHHHHCCCCCCCCCEECCHHHHHHHHHHCCCCEE T ss_conf 99974873267--8999999708931736885787513186799-99997158798988527287999999854699289 Q ss_pred EEECCCCCCCCCCCHHHHHHHHHHHHHHHCCC-CHHHHHHHHHH-CCCCCEEEECCCCCCCCCCCCCCC-CC--CCCCCC Q ss_conf 63046534300023235677888788751445-31777887752-057523442157763103520001-11--356654 Q gi|254780206|r 142 VKADGLCAGKGVVVAATVDEATSAIDRCFQQI-NSTVIIEEYLE-GFEVSFFALCDGKTAIPFTTARDH-KR--IHDGDI 216 (424) Q Consensus 142 VKp~~~agGkGV~i~~~~~e~~~~~~~~~~~~-~~~VliEefl~-G~E~Sv~~i~dG~~~~~l~~~~dy-Kr--~~~~d~ 216 (424) T Consensus 729 vRPSYVLgG~aM~iv~~~eeL~~yl~~a~~~S~~~PVlidky~e~A~E~dVD~v~Dg~~v~i~gI~-EHiE~AGVHSGDs 807 (1089) T TIGR01369 729 VRPSYVLGGRAMEIVYNEEELARYLEEAVEVSPEHPVLIDKYLEDAVEIDVDAVSDGEEVLIPGIM-EHIEEAGVHSGDS 807 (1089) T ss_pred ECCCCCCCCCCHHEECCHHHHHHHHHHHHHHCCCCCEEEEEECCCCEEEEEEEEEECCEEEEEEHH-HHHHHCCCCCCCH T ss_conf 816830033621002678899999999997208997698885288889999899728848996231-2342136761305 Q ss_pred CCCCCCCCEEECCCCCCCCCCEEEECCHHHHHHHHHHHCCCEEEEEEEEEEEEEC-CEEEEEEEEEEECCCCCEEEEEC- Q ss_conf 4444344300001234432220100000899999862046235664454489855-70489998865147751044332- Q gi|254780206|r 217 GPNTGGMGACSPALGMSQELYSTVIQKIILPTIEGMQKEQNPFQGVLFAGLMITE-QGPYLIEYNVRFGDPECQAMMMR- 294 (424) Q Consensus 217 GpnTGGMGa~~p~~~~~~~~~~~i~~~i~~~~~~~l~~~~~~y~G~l~~~~m~t~-~gp~viE~N~R~GDPE~q~ilp~- 294 (424) T Consensus 808 ~-------~~~Pp~~L~~~~~~~i-~~~~~~iA~~L~-----v~Gl~NiQf~~~~E~~~yVIE~NpRASR--tVPFvSKa 872 (1089) T TIGR01369 808 T-------CVLPPQTLSEDIVKRI-KDIVRKIAKELN-----VKGLFNIQFVVKDEGEVYVIEVNPRASR--TVPFVSKA 872 (1089) T ss_pred H-------HCCCCCCCCHHHHHHH-HHHHHHHHHHCC-----CCCCEEEEEEEECCCCEEEEEECCCCCC--CCCCEEEE T ss_conf 3-------1176977788999999-999999998706-----6072224555616996799997174206--65413210 Q ss_pred CCCCCHHHHHHHHHCCC Q ss_conf 65441156665420133 Q gi|254780206|r 295 LESDILEILNSCVHGNL 311 (424) Q Consensus 295 L~~dl~~il~~~~~g~L 311 (424) T Consensus 873 ~Gipl~~~A~~~~~G~~ 889 (1089) T TIGR01369 873 TGIPLAKLAVRVMLGKK 889 (1089) T ss_pred CCCCHHHHHHHHHHCCC T ss_conf 37887999999970882

HHsearch alignment for GI: 254780206 and conserved domain: TIGR01369