>TIGR01161 purK phosphoribosylaminoimidazole carboxylase, ATPase subunit; InterPro: IPR005875 Phosphoribosylaminoimidazole carboxylase is a fusion protein in plants and fungi, but consists of two non-interacting proteins in bacteria, PurK and PurE. This family represents PurK, N5-carboxyaminoimidazole ribonucleotide (N5_CAIR) synthetase, which catalyzes the conversion of 5-aminoimidazole ribonucleotide (AIR), ATP, and bicarbonate to N5-CAIR, ADP, and Pi. PurE converts N5-CAIR to CAIR. In the presence of high concentrations of bicarbonate, PurE is reported able to convert AIR to CAIR directly and without ATP. PurK belongs to the ATP grasp superfamily of C-N ligase enzymes. Each subunit of PurK is composed of three domains (A, B, and C). The B domain contains a flexible, glycine-rich loop (B loop, T123-G130) that is disordered in the sulphate-PurK structure and becomes ordered in the MgADP-PurK structure. MgADP is wedged between the B and C domains, as with all members of the ATP grasp superfamily. Other enzymes in this superfamily contain a conserved Omega loop proposed to interact with the B loop, define the specificity of their nonnucleotide substrate, and protect the acyl phosphate intermediate formed from this substrate. PurK contains a minimal Omega loop without conserved residues. In the reaction catalyzed by PurK, carboxyphosphate is the putative acyl phosphate intermediate. The sulphate of the sulphate ion-liganded PurK interacts electrostatically with Arg 242 and the backbone amide group of Asn 245, components of the J loop of the C domain. This sulphate may reveal the location of the carboxyphosphate binding site. Conserved residues within the C-terminus of the C domain define a pocket that is proposed to bind AIR in collaboration with an N-terminal strand loop helix motif in the A domain (P loop, G8-L1). The P loop is proposed to bind the phosphate of AIR on the basis of similar binding sites observed in PurN and PurE and proposed in PurD and PurT, four other enzymes in the purine pathway .; GO: 0004638 phosphoribosylaminoimidazole carboxylase activity, 0006189 'de novo' IMP biosynthetic process, 0009320 phosphoribosylaminoimidazole carboxylase complex.

Probab=99.81 E-value=9.8e-19 Score=155.40 Aligned_cols=351 Identities=21% Similarity=0.268 Sum_probs=237.2 Q ss_pred EEEEECCCHHHHHHHHHHHHC--CCCCEEEEE-CC-CHHHHHCCE---EEECCCCCHHHHHHHHHHHCCCEEEEC----C Q ss_conf 589988658899999999858--996789995-49-835751170---551287898999999987189799997----9 Q gi|254780206|r 2 RVLLIGSGGREHALAWKIAQS--PLLSELWSI-PG-NPGIAQHAQ---CVAIDIQNHSAIIHFCQEKHIDLVVVG----P 70 (424) Q Consensus 2 kILviGsGgrEhAl~~~l~~s--~~~~~v~~~-pg-N~g~~~~~~---~~~i~~~d~~~i~~~a~~~~iDlvivg----p 70 (424) T Consensus 1 ~vGilGGG----QLG~M~~~aA~~LG~~~~VL~~~~~~PA~q~Ad~~~~v~a~~~d~~~i~~La~~c--DviT~E~Ehv~ 74 (386) T TIGR01161 1 TVGILGGG----QLGRMLALAAKKLGIKVAVLDPDANSPAKQVADSREHVLASFTDPEAIRELAEAC--DVITFEFEHVD 74 (386) T ss_pred CEEEEECC----HHHHHHHHHHHHCCCEEEEECCCCCCCCCCCCCCCCEEEEEECCHHHHHHHHHHC--CEEEEEECCCC T ss_conf 96897188----4899999987127958998548989731112898557998514878999999765--65543101378 Q ss_pred CHHHHHHHHHHHHHCC--CCEEECCHHHHHHHHCCHHHHHHHHHHHHHCCCCCCCC--CCHHHHHHHHCCCCEEEEEEC- Q ss_conf 5578748998986058--80670106665552010235788876531011112234--401111121012420256304- Q gi|254780206|r 71 ELPLVNGISDALNAAG--FKVFGPSQRAAKLESSKSFAKKFCTKYGIPTATYQHFS--DPMKAKQYVQNKSMPIVVKAD- 145 (424) Q Consensus 71 E~pL~~gi~d~l~~~g--i~v~Gp~~~aa~le~sK~~~K~~l~~~gIPt~~~~~~~--~~~ea~~~~~~~g~PvVVKp~- 145 (424) T Consensus 75 ~~~L-----~~L~~~g~~~~~~-P~~~~l~~~~dk~~qK~~L~~~g~~vp~f~~~~~~~~~~~~~~~~~~g~p~VlK~~~ 148 (386) T TIGR01161 75 VEAL-----EKLEARGDKVKVR-PSPEALAIIQDKLTQKQFLQKLGLPVPPFVVIEIKDEEELDSALQELGFPVVLKARR 148 (386) T ss_pred CHHH-----HHHHHCCCEEEEE-CCHHHHHHHHCHHHHHHHHHHCCCCCCCCCEEECCCHHHHHHHHHHCCCCEEEEEEE T ss_conf 5678-----9998359847760-388999988365899999996689988412022368425789998739847998420 Q ss_pred CCCCCCCCCCHHHHHHHHHHHHHHHCCCCHHHHHHHHHHC-CCCCEEEEC--CCCCCCCCCCCCCCCCCCCCCCCCCCCC Q ss_conf 6534300023235677888788751445317778877520-575234421--5776310352000111356654444434 Q gi|254780206|r 146 GLCAGKGVVVAATVDEATSAIDRCFQQINSTVIIEEYLEG-FEVSFFALC--DGKTAIPFTTARDHKRIHDGDIGPNTGG 222 (424) Q Consensus 146 ~~agGkGV~i~~~~~e~~~~~~~~~~~~~~~VliEefl~G-~E~Sv~~i~--dG~~~~~l~~~~dyKr~~~~d~GpnTGG 222 (424) T Consensus 149 gGYDGrGq~~i~~~~~~~~~~~~~-~~~~~~~~~E~fV~F~~Elsv~vaR~~~G~-~~~YP~ven~~---~ddagIl--- 220 (386) T TIGR01161 149 GGYDGRGQFVIKSEADLPQALKEL-GDKEEELIVEEFVPFERELSVIVARSADGE-IAFYPVVENIH---QDDAGIL--- 220 (386) T ss_pred CCCCCCCCEEECCHHHHHHHHHHC-CCCCEEEEEEECCCCCEEEEEEEEECCCCC-EEECCCEEEEE---ECCCCEE--- T ss_conf 652773108974743288999852-888405898523562006999999778974-88828612356---5277877--- Q ss_pred CCEEECCCCCCCCC---CEEEECCHHHHHHHHHHHCCCEEEEEEEEEEEEE--CCE-----EEEEEEEEEECCCCCEEEE Q ss_conf 43000012344322---2010000089999986204623566445448985--570-----4899988651477510443 Q gi|254780206|r 223 MGACSPALGMSQEL---YSTVIQKIILPTIEGMQKEQNPFQGVLFAGLMIT--EQG-----PYLIEYNVRFGDPECQAMM 292 (424) Q Consensus 223 MGa~~p~~~~~~~~---~~~i~~~i~~~~~~~l~~~~~~y~G~l~~~~m~t--~~g-----p~viE~N~R~GDPE~q~il 292 (424) T Consensus 221 ~~~~aPAPa~p~~~~Q~~~~A-~~~A~~~~~-----~L~~VG~~avE~F~~Pa~dGP~P~~LLvNElAPR~HNSGHyTlD 294 (386) T TIGR01161 221 RLVVAPAPAVPDALVQQQKKA-QELARRLAE-----ELDYVGVLAVEMFLLPAKDGPEPDELLVNELAPRPHNSGHYTLD 294 (386) T ss_pred EEEEECCCCCCHHHHHHHHHH-HHHHHHHHH-----HCCCEEEEEEEEEEECCCCCCCCCCEEEEEECCCCCCCHHHHHH T ss_conf 898633777834578999999-999999998-----61961788899983068878951205661025788984126566 Q ss_pred ECCCCCCHHHHHHHHHCCCCC--CCCCCCC-CCEEEEEECCCCCCCCCCCCC-CCCCCCCCCCCCEEEEEEEEEECCEEE Q ss_conf 326544115666542013333--2123444-420675422544668775797-624876668986899833587788799 Q gi|254780206|r 293 MRLESDILEILNSCVHGNLHN--THINWKA-EYALTVVVATKGYPEEYPHGT-IISKIPQNTGTTQLFHAGTAIVNNNLT 368 (424) Q Consensus 293 p~L~~dl~~il~~~~~g~L~~--~~~~~~~-~~~v~Vvlas~GYP~~~~kg~-~I~~l~~~~~~~~ifhagt~~~~g~l~ 368 (424) T Consensus 295 gc~tSQFE~hLRAi~~LPLg~~~t~~~~PTT~~~MVNlLG~~~~-~~~~~~~~~~~~~P~--a~lhwYGK~E~------- 364 (386) T TIGR01161 295 GCSTSQFEQHLRAILGLPLGSIFTELLLPTTQAVMVNLLGTEGP-DEVAPLWEELLALPG--AKLHWYGKAEV------- 364 (386) T ss_pred HHHHHHHHHHHHHHCCCCCCCCCCCCCCCCCEEEEEEEECCCCC-CHHHHHHHHHHHCCC--CEEEEECCEEE------- T ss_conf 54331799999997088987444100278430578988335676-266788999973898--47887546003------- Q ss_pred ECCCC-EEEEEEECCCHHHHHH Q ss_conf 81880-7999996289899999 Q gi|254780206|r 369 ANGGR-VLSATALGKTITESRE 389 (424) Q Consensus 369 t~GGR-VL~vv~~g~~l~eA~~ 389 (424) T Consensus 365 -RpgRK~GH~n~~~~~~~~~~~ 385 (386) T TIGR01161 365 -RPGRKVGHVNLVGSDLEELEQ 385 (386) T ss_pred -CCCCCEEEEEECCCCHHHHCC T ss_conf -789610168633868355304

HHsearch alignment for GI: 254780206 and conserved domain: TIGR01161