ID   GUAC_CITK8              Reviewed;         347 AA.
AC   A8ALJ2;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-OCT-2007, sequence version 1.
DT   02-SEP-2026, entry version 93.
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=CKO_03271;
OS   Citrobacter koseri (strain ATCC BAA-895 / CDC 4225-83 / SGSC4696).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Citrobacter.
OX   NCBI_TaxID=290338;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-895 / CDC 4225-83 / SGSC4696;
RG   The Citrobacter koseri Genome Sequencing Project;
RA   McClelland M., Sanderson E.K., Porwollik S., Spieth J., Clifton W.S.,
RA   Latreille P., Courtney L., Wang C., Pepin K., Bhonagiri V., Nash W.,
RA   Johnson M., Thiruvilangam P., Wilson R.;
RL   Submitted (AUG-2007) to the EMBL/GenBank/DDBJ databases.
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 + NH4(+) + NADP(+) = GMP + NADPH + 2 H(+);
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; CP000822; ABV14355.1; -; Genomic_DNA.
DR   RefSeq; WP_012134060.1; NC_009792.1.
DR   AlphaFoldDB; A8ALJ2; -.
DR   SMR; A8ALJ2; -.
DR   STRING; 290338.CKO_03271; -.
DR   GeneID; 45137045; -.
DR   KEGG; cko:CKO_03271; -.
DR   HOGENOM; CLU_022552_5_3_6; -.
DR   OrthoDB; 9805398at2; -.
DR   Proteomes; UP000008148; Chromosome.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
DR   GO; GO:1902560; C:GMP reductase complex; IEA:InterPro.
DR   GO; GO:0003920; F:GMP reductase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0006163; P:purine nucleotide metabolic process; IEA:UniProtKB-UniRule.
DR   CDD; cd00381; IMPDH; 1.
DR   FunFam; 3.20.20.70:FF:000012; GMP reductase; 1.
DR   Gene3D; 3.20.20.70; Aldolase class I; 1.
DR   HAMAP; MF_00596; GMP_reduct_type1; 1.
DR   InterPro; IPR013785; Aldolase_TIM.
DR   InterPro; IPR050139; GMP_reductase.
DR   InterPro; IPR005993; GMPR.
DR   InterPro; IPR015875; IMP_DH/GMP_Rdtase_CS.
DR   InterPro; IPR001093; IMP_DH_GMPRt.
DR   NCBIfam; TIGR01305; GMP_reduct_1; 1.
DR   NCBIfam; NF003470; PRK05096.1; 1.
DR   PANTHER; PTHR43170; GMP REDUCTASE; 1.
DR   PANTHER; PTHR43170:SF5; GMP REDUCTASE; 1.
DR   Pfam; PF00478; IMPDH; 1.
DR   PIRSF; PIRSF000235; GMP_reductase; 1.
DR   SMART; SM01240; IMPDH; 1.
DR   SUPFAM; SSF51412; Inosine monophosphate dehydrogenase (IMPDH); 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..347
FT                   /note="GMP reductase"
FT                   /id="PRO_1000025610"
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   347 AA;  37358 MW;  2F338597E56FF791 CRC64;
     MRIEEDLKLG FKDVLIRPKR STLKSRSDVE LERQFTFKHS GQTWSGVPII AANMDTVGTF
     EMASALASFD ILTAVHKHYS VEDWNAFTST ASEDVLRHVM VSTGTSDADF EKTKQILAQS
     PALNFVCIDV ANGYSEHFVQ FVSKAREAWP TKTICAGNVV TGEMCEELVL SGADIVKVGI
     GPGSVCTTRV KTGVGYPQLS AVIECADAAH GLGGMIVSDG GCTMPGDVAK AFGGGADFVM
     LGGMLAGHEE SGGKIVEENG EKFMLFYGMS SESAMTRHVG GVAQYRAAEG KTVKLPLRGP
     VEYTARDILG GLRSACTYVG ASRLKELTKR TTFIRVQEQE NRVFNSL
//