ID   GUAC_BUCAI              Reviewed;         349 AA.
AC   P57300;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-2000, sequence version 1.
DT   03-AUG-2022, entry version 114.
DE   RecName: Full=GMP reductase;
DE            EC=1.7.1.7;
DE   AltName: Full=Guanosine 5'-monophosphate oxidoreductase;
DE            Short=Guanosine monophosphate reductase;
GN   Name=guaC; OrderedLocusNames=BU204;
OS   Buchnera aphidicola subsp. Acyrthosiphon pisum (strain APS) (Acyrthosiphon
OS   pisum symbiotic bacterium).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=107806;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=APS;
RX   PubMed=10993077; DOI=10.1038/35024074;
RA   Shigenobu S., Watanabe H., Hattori M., Sakaki Y., Ishikawa H.;
RT   "Genome sequence of the endocellular bacterial symbiont of aphids Buchnera
RT   sp. APS.";
RL   Nature 407:81-86(2000).
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 (By similarity).
CC       {ECO:0000250}.
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;
CC   -!- SUBUNIT: Homotetramer. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the IMPDH/GMPR family. GuaC type 1 subfamily.
CC       {ECO:0000305}.
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; BA000003; BAB12921.1; -; Genomic_DNA.
DR   RefSeq; NP_240035.1; NC_002528.1.
DR   RefSeq; WP_009874161.1; NC_002528.1.
DR   AlphaFoldDB; P57300; -.
DR   SMR; P57300; -.
DR   STRING; 107806.10038886; -.
DR   EnsemblBacteria; BAB12921; BAB12921; BAB12921.
DR   KEGG; buc:BU204; -.
DR   PATRIC; fig|107806.10.peg.215; -.
DR   eggNOG; COG0516; Bacteria.
DR   HOGENOM; CLU_022552_5_3_6; -.
DR   OMA; AYKEYFG; -.
DR   Proteomes; UP000001806; Chromosome.
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; Reference proteome.
FT   CHAIN           1..349
FT                   /note="GMP reductase"
FT                   /id="PRO_0000093732"
FT   ACT_SITE        186
FT                   /note="Thioimidate intermediate"
FT                   /evidence="ECO:0000250"
FT   BINDING         108..131
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000250"
FT   BINDING         181
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250"
FT   BINDING         183
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250"
FT   BINDING         216..239
FT                   /ligand="NADP(+)"
FT                   /ligand_id="ChEBI:CHEBI:58349"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   349 AA;  38320 MW;  D4D109BD6B493D72 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 KTVKIPFRGG
     VDSTIRDILG GLRSSCTYVG AEKLKELTKR TTFIRVTEQE NCIFNAFKE