ID   PURK_ECOLI              Reviewed;         355 AA.
AC   P09029; Q2MBQ7;
DT   01-NOV-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1997, sequence version 2.
DT   04-NOV-2026, entry version 196.
DE   RecName: Full=N5-carboxyaminoimidazole ribonucleotide synthase {ECO:0000255|HAMAP-Rule:MF_01928, ECO:0000305};
DE            Short=N5-CAIR synthase {ECO:0000255|HAMAP-Rule:MF_01928, ECO:0000305};
DE            EC=6.3.4.18 {ECO:0000255|HAMAP-Rule:MF_01928, ECO:0000269|PubMed:8117684};
DE   AltName: Full=5-(carboxyamino)imidazole ribonucleotide synthetase {ECO:0000255|HAMAP-Rule:MF_01928, ECO:0000305};
GN   Name=purK {ECO:0000255|HAMAP-Rule:MF_01928};
GN   OrderedLocusNames=b0522 {ECO:0000312|EMBL:AAC73624.1}, JW0511
GN   {ECO:0000312|EMBL:BAE76299.1};
OS   Escherichia coli (strain K12).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=83333;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=K12;
RX   PubMed=2464576; DOI=10.1128/jb.171.1.205-212.1989;
RA   Tiedeman A.A., Keyhani J., Kamholz J., Daum H.A. III, Gots J.S.,
RA   Smith J.M.;
RT   "Nucleotide sequence analysis of the purEK operon encoding 5'-
RT   phosphoribosyl-5-aminoimidazole carboxylase of Escherichia coli K-12.";
RL   J. Bacteriol. 171:205-212(1989).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2644189; DOI=10.1128/jb.171.1.198-204.1989;
RA   Watanabe W., Sampei G., Aiba A., Mizobuchi K.;
RT   "Identification and sequence analysis of Escherichia coli purE and purK
RT   genes encoding 5'-phosphoribosyl-5-amino-4-imidazole carboxylase for de
RT   novo purine biosynthesis.";
RL   J. Bacteriol. 171:198-204(1989).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RA   Chung E., Allen E., Araujo R., Aparicio A.M., Davis K., Duncan M.,
RA   Federspiel N., Hyman R., Kalman S., Komp C., Kurdi O., Lew H., Lin D.,
RA   Namath A., Oefner P., Roberts D., Schramm S., Davis R.W.;
RT   "Sequence of minutes 4-25 of Escherichia coli.";
RL   Submitted (JAN-1997) to the EMBL/GenBank/DDBJ databases.
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA   Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA   Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA   Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA   Shao Y.;
RT   "The complete genome sequence of Escherichia coli K-12.";
RL   Science 277:1453-1462(1997).
RN   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=16738553; DOI=10.1038/msb4100049;
RA   Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA   Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT   "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT   and W3110.";
RL   Mol. Syst. Biol. 2:E1-E5(2006).
RN   [6]
RP   PROTEIN SEQUENCE OF 1-20.
RX   PubMed=1534690; DOI=10.1021/bi00136a016;
RA   Meyer E., Leonard N.J., Bhat B., Stubbe J., Smith J.M.;
RT   "Purification and characterization of the purE, purK, and purC gene
RT   products: identification of a previously unrecognized energy requirement in
RT   the purine biosynthetic pathway.";
RL   Biochemistry 31:5022-5032(1992).
RN   [7]
RP   FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, AND PATHWAY.
RX   PubMed=8117684; DOI=10.1021/bi00174a038;
RA   Mueller E.J., Meyer E., Rudolph J., Davisson V.J., Stubbe J.;
RT   "N5-carboxyaminoimidazole ribonucleotide: evidence for a new intermediate
RT   and two new enzymatic activities in the de novo purine biosynthetic pathway
RT   of Escherichia coli.";
RL   Biochemistry 33:2269-2278(1994).
RN   [8]
RP   X-RAY CRYSTALLOGRAPHY IN COMPLEX WITH ATP ANALOG, AND SUBUNIT.
RX   PubMed=10569930; DOI=10.1021/bi991618s;
RA   Thoden J.B., Kappock T.J., Stubbe J., Holden H.M.;
RT   "Three-dimensional structure of N5-carboxyaminoimidazole ribonucleotide
RT   synthetase: a member of the ATP grasp protein superfamily.";
RL   Biochemistry 38:15480-15492(1999).
RN   [9]
RP   X-RAY CRYSTALLOGRAPHY IN COMPLEX WITH ATP, AND SUBUNIT.
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=19053251; DOI=10.1021/bi801734z;
RA   Thoden J.B., Holden H.M., Firestine S.M.;
RT   "Structural analysis of the active site geometry of N5-
RT   carboxyaminoimidazole ribonucleotide synthetase from Escherichia coli.";
RL   Biochemistry 47:13346-13353(2008).
CC   -!- FUNCTION: Catalyzes the ATP-dependent conversion of 5-aminoimidazole
CC       ribonucleotide (AIR) and HCO(3)(-) to N5-carboxyaminoimidazole
CC       ribonucleotide (N5-CAIR). {ECO:0000255|HAMAP-Rule:MF_01928,
CC       ECO:0000269|PubMed:8117684}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5-amino-1-(5-phospho-beta-D-ribosyl)imidazole +
CC         hydrogencarbonate + ATP = 5-carboxyamino-1-(5-phospho-D-
CC         ribosyl)imidazole + ADP + phosphate + 2 H(+); Xref=Rhea:RHEA:19317,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:17544, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58730, ChEBI:CHEBI:137981,
CC         ChEBI:CHEBI:456216; EC=6.3.4.18; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01928, ECO:0000269|PubMed:8117684};
CC   -!- PATHWAY: Purine metabolism; IMP biosynthesis via de novo pathway; 5-
CC       amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate from 5-amino-1-(5-
CC       phospho-D-ribosyl)imidazole (N5-CAIR route): step 1/2.
CC       {ECO:0000255|HAMAP-Rule:MF_01928, ECO:0000269|PubMed:8117684}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01928,
CC       ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251}.
CC   -!- SIMILARITY: Belongs to the PurK/PurT family. {ECO:0000255|HAMAP-
CC       Rule:MF_01928, ECO:0000305}.
CC   -!- CAUTION: Was originally thought to be the ATPase subunit of
CC       phosphoribosylaminoimidazole carboxylase, with catalytic subunit PurE.
CC       {ECO:0000305|PubMed:2464576}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; X12982; CAA31421.1; -; Genomic_DNA.
DR   EMBL; M19657; AAA24450.1; -; Genomic_DNA.
DR   EMBL; U82664; AAB40275.1; -; Genomic_DNA.
DR   EMBL; U00096; AAC73624.1; -; Genomic_DNA.
DR   EMBL; AP009048; BAE76299.1; -; Genomic_DNA.
DR   PIR; JU0001; DCECPK.
DR   RefSeq; NP_415055.1; NC_000913.3.
DR   RefSeq; WP_000815571.1; NZ_CP009789.1.
DR   PDB; 1B6R; X-ray; 2.10 A; A=1-355.
DR   PDB; 1B6S; X-ray; 2.50 A; A/B/C/D=1-355.
DR   PDB; 3ETH; X-ray; 1.60 A; A/B=1-355.
DR   PDB; 3ETJ; X-ray; 1.60 A; A/B=1-355.
DR   AlphaFoldDB; P09029; -.
DR   MDposit; P09029; -.
DR   SMR; P09029; -.
DR   BioGRID; 4259875; 22.
DR   BioGRID; 849541; 9.
DR   FunCoup; P09029; 568.
DR   IntAct; P09029; 5.
DR   STRING; 511145.b0522; -.
DR   jPOST; P09029; -.
DR   PaxDb; 511145-b0522; -.
DR   EnsemblBacteria; AAC73624; AAC73624; b0522.
DR   GeneID; 945153; -.
DR   KEGG; ecj:JW0511; -.
DR   KEGG; eco:b0522; -.
DR   KEGG; ecoc:C3026_02560; -.
DR   PATRIC; fig|1411691.4.peg.1756; -.
DR   EchoBASE; EB0789; -.
DR   eggNOG; COG0026; Bacteria.
DR   HOGENOM; CLU_011534_0_0_6; -.
DR   InParanoid; P09029; -.
DR   OMA; AACCPVH; -.
DR   OrthoDB; 9804625at2; -.
DR   PhylomeDB; P09029; -.
DR   BioCyc; EcoCyc:PURK-MONOMER; -.
DR   BioCyc; MetaCyc:PURK-MONOMER; -.
DR   BRENDA; 6.3.4.18; 2026.
DR   SABIO-RK; P09029; -.
DR   UniPathway; UPA00074; UER00942.
DR   EvolutionaryTrace; P09029; -.
DR   PRO; PR:P09029; -.
DR   Proteomes; UP000000625; Chromosome.
DR   AbasyAtlas; P09029; -.
DR   GO; GO:0005829; C:cytosol; IDA:EcoCyc.
DR   GO; GO:0034028; F:5-(carboxyamino)imidazole ribonucleotide synthase activity; IDA:EcoCyc.
DR   GO; GO:0005524; F:ATP binding; IDA:EcoCyc.
DR   GO; GO:0046872; F:metal ion binding; IEA:InterPro.
DR   GO; GO:0004638; F:phosphoribosylaminoimidazole carboxylase activity; IDA:EcoliWiki.
DR   GO; GO:0006189; P:'de novo' IMP biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0006144; P:purine nucleobase metabolic process; IBA:GO_Central.
DR   FunFam; 3.30.1490.20:FF:000021; N5-carboxyaminoimidazole ribonucleotide synthase; 1.
DR   FunFam; 3.30.470.20:FF:000034; N5-carboxyaminoimidazole ribonucleotide synthase; 1.
DR   FunFam; 3.40.50.20:FF:000017; N5-carboxyaminoimidazole ribonucleotide synthase; 1.
DR   Gene3D; 3.40.50.20; -; 1.
DR   Gene3D; 3.30.1490.20; ATP-grasp fold, A domain; 1.
DR   Gene3D; 3.30.470.20; ATP-grasp fold, B domain; 1.
DR   HAMAP; MF_01928; PurK; 1.
DR   InterPro; IPR011761; ATP-grasp.
DR   InterPro; IPR003135; ATP-grasp_carboxylate-amine.
DR   InterPro; IPR013815; ATP_grasp_subdomain_1.
DR   InterPro; IPR016185; PreATP-grasp_dom_sf.
DR   InterPro; IPR005875; PurK.
DR   InterPro; IPR040686; PurK_C.
DR   InterPro; IPR054350; PurT/PurK_preATP-grasp.
DR   InterPro; IPR011054; Rudment_hybrid_motif.
DR   NCBIfam; NF004678; purK; 1.
DR   NCBIfam; TIGR01161; purK; 1.
DR   PANTHER; PTHR11609:SF5; PHOSPHORIBOSYLAMINOIMIDAZOLE CARBOXYLASE; 1.
DR   PANTHER; PTHR11609; PURINE BIOSYNTHESIS PROTEIN 6/7, PUR6/7; 1.
DR   Pfam; PF02222; ATP-grasp; 1.
DR   Pfam; PF17769; PurK_C; 1.
DR   Pfam; PF22660; RS_preATP-grasp-like; 1.
DR   SUPFAM; SSF56059; Glutathione synthetase ATP-binding domain-like; 1.
DR   SUPFAM; SSF52440; PreATP-grasp domain; 1.
DR   SUPFAM; SSF51246; Rudiment single hybrid motif; 1.
DR   PROSITE; PS50975; ATP_GRASP; 1.
PE   1: Evidence at protein level;
KW   3D-structure; ATP-binding; Direct protein sequencing; Ligase;
KW   Nucleotide-binding; Purine biosynthesis; Reference proteome.
FT   CHAIN           1..355
FT                   /note="N5-carboxyaminoimidazole ribonucleotide synthase"
FT                   /id="PRO_0000074997"
FT   DOMAIN          84..267
FT                   /note="ATP-grasp"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928"
FT   BINDING         80
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         120
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         125..131
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         153..156
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         161
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         184
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   BINDING         237..238
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01928,
FT                   ECO:0000269|PubMed:10569930, ECO:0000269|PubMed:19053251"
FT   CONFLICT        64..65
FT                   /note="RH -> PD (in Ref. 1; CAA31421)"
FT                   /evidence="ECO:0000305"
FT   STRAND          3..8
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           11..20
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           21..23
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          26..30
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           36..38
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           41..43
FT                   /evidence="ECO:0007829|PDB:3ETJ"
FT   STRAND          44..49
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           57..63
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   TURN            69..72
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           73..78
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           80..89
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          97..100
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           103..105
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           106..113
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          115..124
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   TURN            127..130
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          131..135
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   TURN            136..138
FT                   /evidence="ECO:0007829|PDB:1B6S"
FT   HELIX           139..141
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           144..146
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   TURN            147..149
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          150..154
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          159..168
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          174..176
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          180..185
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          188..194
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           200..217
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          221..230
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          233..242
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           245..247
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           250..253
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          254..256
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           258..266
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           272..275
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          280..287
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           292..296
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          301..304
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   STRAND          314..321
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           325..335
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           336..338
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           341..343
FT                   /evidence="ECO:0007829|PDB:3ETH"
FT   HELIX           344..353
FT                   /evidence="ECO:0007829|PDB:3ETH"
SQ   SEQUENCE   355 AA;  39461 MW;  93464E111E29AD9C CRC64;
     MKQVCVLGNG QLGRMLRQAG EPLGIAVWPV GLDAEPAAVP FQQSVITAEI ERWPETALTR
     ELARHPAFVN RDVFPIIADR LTQKQLFDKL HLPTAPWQLL AERSEWPAVF DRLGELAIVK
     RRTGGYDGRG QWRLRANETE QLPAECYGEC IVEQGINFSG EVSLVGARGF DGSTVFYPLT
     HNLHQDGILR TSVAFPQANA QQQAQAEEML SAIMQELGYV GVMAMECFVT PQGLLINELA
     PRVHNSGHWT QNGASISQFE LHLRAITDLP LPQPVVNNPS VMINLIGSDV NYDWLKLPLV
     HLHWYDKEVR PGRKVGHLNL TDSDTSRLTA TLEALIPLLP PEYASGVIWA QSKFG
//