ID   GUAC_BUCAT              Reviewed;         349 AA.
AC   B8D7A8;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-MAR-2009, sequence version 1.
DT   03-AUG-2022, entry version 64.
DE   RecName: Full=GMP reductase {ECO:0000255|HAMAP-Rule:MF_00596};
DE            EC=1.7.1.7 {ECO:0000255|HAMAP-Rule:MF_00596};
DE   AltName: Full=Guanosine 5'-monophosphate oxidoreductase {ECO:0000255|HAMAP-Rule:MF_00596};
DE            Short=Guanosine monophosphate reductase {ECO:0000255|HAMAP-Rule:MF_00596};
GN   Name=guaC {ECO:0000255|HAMAP-Rule:MF_00596};
GN   OrderedLocusNames=BUAPTUC7_203;
OS   Buchnera aphidicola subsp. Acyrthosiphon pisum (strain Tuc7).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=561501;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Tuc7;
RX   PubMed=19150844; DOI=10.1126/science.1167140;
RA   Moran N.A., McLaughlin H.J., Sorek R.;
RT   "The dynamics and time scale of ongoing genomic erosion in symbiotic
RT   bacteria.";
RL   Science 323:379-382(2009).
CC   -!- FUNCTION: Catalyzes the irreversible NADPH-dependent deamination of GMP
CC       to IMP. It functions in the conversion of nucleobase, nucleoside and
CC       nucleotide derivatives of G to A nucleotides, and in maintaining the
CC       intracellular balance of A and G nucleotides. {ECO:0000255|HAMAP-
CC       Rule:MF_00596}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=IMP + NADP(+) + NH4(+) = GMP + 2 H(+) + NADPH;
CC         Xref=Rhea:RHEA:17185, ChEBI:CHEBI:15378, ChEBI:CHEBI:28938,
CC         ChEBI:CHEBI:57783, ChEBI:CHEBI:58053, ChEBI:CHEBI:58115,
CC         ChEBI:CHEBI:58349; EC=1.7.1.7; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00596};
CC   -!- SUBUNIT: Homotetramer. {ECO:0000255|HAMAP-Rule:MF_00596}.
CC   -!- SIMILARITY: Belongs to the IMPDH/GMPR family. GuaC type 1 subfamily.
CC       {ECO:0000255|HAMAP-Rule:MF_00596}.
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DR   EMBL; CP001158; ACL30023.1; -; Genomic_DNA.
DR   RefSeq; WP_012619470.1; NC_011834.1.
DR   AlphaFoldDB; B8D7A8; -.
DR   SMR; B8D7A8; -.
DR   KEGG; bau:BUAPTUC7_203; -.
DR   HOGENOM; CLU_022552_5_3_6; -.
DR   OMA; AYKEYFG; -.
DR   GO; GO:1902560; C:GMP reductase complex; IEA:InterPro.
DR   GO; GO:0003920; F:GMP reductase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0006163; P:purine nucleotide metabolic process; IEA:UniProtKB-UniRule.
DR   CDD; cd00381; IMPDH; 1.
DR   Gene3D; 3.20.20.70; -; 1.
DR   HAMAP; MF_00596; GMP_reduct_type1; 1.
DR   InterPro; IPR013785; Aldolase_TIM.
DR   InterPro; IPR005993; GMPR.
DR   InterPro; IPR015875; IMP_DH/GMP_Rdtase_CS.
DR   InterPro; IPR001093; IMP_DH_GMPRt.
DR   Pfam; PF00478; IMPDH; 1.
DR   PIRSF; PIRSF000235; GMP_reductase; 1.
DR   TIGRFAMs; TIGR01305; GMP_reduct_1; 1.
DR   PROSITE; PS00487; IMP_DH_GMP_RED; 1.
PE   3: Inferred from homology;
KW   Metal-binding; NADP; Oxidoreductase; Potassium.
FT   CHAIN           1..349
FT                   /note="GMP reductase"
FT                   /id="PRO_1000146984"
FT   ACT_SITE        186
FT                   /note="Thioimidate intermediate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00596"
FT   BINDING         108..131
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00596"
FT   BINDING         181
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00596"
FT   BINDING         183
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00596"
FT   BINDING         216..239
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00596"
SQ   SEQUENCE   349 AA;  38350 MW;  D4CA7F661D893D72 CRC64;
     MRIEEDIKLG FKDVLIRPKR SILKSRSQVN LARCFSFKYS ASIWSGIPII AANMDTIGTF
     EMVKSLSKFN ILTAVHKYYS FEEWKNFVCL SSKEILNHVI VSIGTSNIDF LKIKKIFLLS
     SELKYICIDV ANGYSEHIVS FLKLVRDYFP DKIICAGNVV TGEMVEELIL SGADIVKVGI
     GPGSVCTTRV KTGVGYPQLS AIIECADAAH GLNGQIISDG GCTVSGDIAK AFGGGADFVM
     LGGMLSGHKE CSGDIIEEKS KKYMIFYGMS SVSAMQRYEG KIAGYRASEG KTVKIPFRGS
     VDSTIRDILG GLRSSCTYVG AEKLKELTKR TTFIRVTEQE NCIFNAFKE