ID   IMDH_RHITR              Reviewed;         498 AA.
AC   Q9KH33;
DT   01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   24-JAN-2024, entry version 106.
DE   RecName: Full=Inosine-5'-monophosphate dehydrogenase {ECO:0000255|HAMAP-Rule:MF_01964};
DE            Short=IMP dehydrogenase {ECO:0000255|HAMAP-Rule:MF_01964};
DE            Short=IMPD {ECO:0000255|HAMAP-Rule:MF_01964};
DE            Short=IMPDH {ECO:0000255|HAMAP-Rule:MF_01964};
DE            EC=1.1.1.205 {ECO:0000255|HAMAP-Rule:MF_01964};
GN   Name=guaB {ECO:0000255|HAMAP-Rule:MF_01964};
OS   Rhizobium tropici.
OC   Bacteria; Pseudomonadota; Alphaproteobacteria; Hyphomicrobiales;
OC   Rhizobiaceae; Rhizobium/Agrobacterium group; Rhizobium.
OX   NCBI_TaxID=398;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=899;
RX   PubMed=11059489; DOI=10.1094/mpmi.2000.13.11.1228;
RA   Riccillo P.M., Collavino M.M., Grasso D.H., England R., de Bruijn F.J.,
RA   Aguilar O.M.;
RT   "A guaB mutant strain of Rhizobium tropici CIAT899 pleiotropically
RT   defective in thermal tolerance and symbiosis.";
RL   Mol. Plant Microbe Interact. 13:1228-1236(2000).
CC   -!- FUNCTION: Catalyzes the conversion of inosine 5'-phosphate (IMP) to
CC       xanthosine 5'-phosphate (XMP), the first committed and rate-limiting
CC       step in the de novo synthesis of guanine nucleotides, and therefore
CC       plays an important role in the regulation of cell growth.
CC       {ECO:0000255|HAMAP-Rule:MF_01964}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2O + IMP + NAD(+) = H(+) + NADH + XMP; Xref=Rhea:RHEA:11708,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:57464,
CC         ChEBI:CHEBI:57540, ChEBI:CHEBI:57945, ChEBI:CHEBI:58053;
CC         EC=1.1.1.205; Evidence={ECO:0000255|HAMAP-Rule:MF_01964};
CC   -!- COFACTOR:
CC       Name=K(+); Xref=ChEBI:CHEBI:29103; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01964};
CC   -!- ACTIVITY REGULATION: Mycophenolic acid (MPA) is a non-competitive
CC       inhibitor that prevents formation of the closed enzyme conformation by
CC       binding to the same site as the amobile flap. In contrast, mizoribine
CC       monophosphate (MZP) is a competitive inhibitor that induces the closed
CC       conformation. MPA is a potent inhibitor of mammalian IMPDHs but a poor
CC       inhibitor of the bacterial enzymes. MZP is a more potent inhibitor of
CC       bacterial IMPDH. {ECO:0000255|HAMAP-Rule:MF_01964}.
CC   -!- PATHWAY: Purine metabolism; XMP biosynthesis via de novo pathway; XMP
CC       from IMP: step 1/1. {ECO:0000255|HAMAP-Rule:MF_01964}.
CC   -!- SUBUNIT: Homotetramer. {ECO:0000255|HAMAP-Rule:MF_01964}.
CC   -!- SIMILARITY: Belongs to the IMPDH/GMPR family. {ECO:0000255|HAMAP-
CC       Rule:MF_01964}.
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DR   EMBL; AF272827; AAF85967.1; -; Genomic_DNA.
DR   UniPathway; UPA00601; UER00295.
DR   GO; GO:0003938; F:IMP dehydrogenase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0006177; P:GMP biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd04601; CBS_pair_IMPDH; 1.
DR   CDD; cd00381; IMPDH; 1.
DR   Gene3D; 3.20.20.70; Aldolase class I; 1.
DR   HAMAP; MF_01964; IMPDH; 1.
DR   InterPro; IPR013785; Aldolase_TIM.
DR   InterPro; IPR000644; CBS_dom.
DR   InterPro; IPR046342; CBS_dom_sf.
DR   InterPro; IPR005990; IMP_DH.
DR   InterPro; IPR015875; IMP_DH/GMP_Rdtase_CS.
DR   InterPro; IPR001093; IMP_DH_GMPRt.
DR   NCBIfam; TIGR01302; IMP_dehydrog; 1.
DR   PANTHER; PTHR11911:SF111; INOSINE-5'-MONOPHOSPHATE DEHYDROGENASE; 1.
DR   PANTHER; PTHR11911; INOSINE-5-MONOPHOSPHATE DEHYDROGENASE RELATED; 1.
DR   Pfam; PF00571; CBS; 2.
DR   Pfam; PF00478; IMPDH; 1.
DR   PIRSF; PIRSF000130; IMPDH; 1.
DR   SMART; SM00116; CBS; 2.
DR   SMART; SM01240; IMPDH; 1.
DR   SUPFAM; SSF54631; CBS-domain pair; 1.
DR   SUPFAM; SSF51412; Inosine monophosphate dehydrogenase (IMPDH); 1.
DR   PROSITE; PS51371; CBS; 2.
DR   PROSITE; PS00487; IMP_DH_GMP_RED; 1.
PE   3: Inferred from homology;
KW   CBS domain; GMP biosynthesis; Metal-binding; NAD; Oxidoreductase;
KW   Potassium; Purine biosynthesis; Repeat.
FT   CHAIN           1..498
FT                   /note="Inosine-5'-monophosphate dehydrogenase"
FT                   /id="PRO_0000093704"
FT   DOMAIN          98..155
FT                   /note="CBS 1"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   DOMAIN          159..216
FT                   /note="CBS 2"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   ACT_SITE        310
FT                   /note="Thioimidate intermediate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   ACT_SITE        406
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         253
FT                   /ligand="NAD(+)"
FT                   /ligand_id="ChEBI:CHEBI:57540"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         303..305
FT                   /ligand="NAD(+)"
FT                   /ligand_id="ChEBI:CHEBI:57540"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         305
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         307
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         308
FT                   /ligand="IMP"
FT                   /ligand_id="ChEBI:CHEBI:58053"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         310
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         343..345
FT                   /ligand="IMP"
FT                   /ligand_id="ChEBI:CHEBI:58053"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         366..367
FT                   /ligand="IMP"
FT                   /ligand_id="ChEBI:CHEBI:58053"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         390..394
FT                   /ligand="IMP"
FT                   /ligand_id="ChEBI:CHEBI:58053"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         421
FT                   /ligand="IMP"
FT                   /ligand_id="ChEBI:CHEBI:58053"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         475
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         476
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
FT   BINDING         477
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /ligand_note="ligand shared between two tetrameric
FT                   partners"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01964"
SQ   SEQUENCE   498 AA;  52838 MW;  0A99E38B1078ED73 CRC64;
     MARIIETSTG LDALTFDDVL LQPGHSEVMP GQTNIATRIA QDIELNVPIL SAAMDTVTES
     RLAIAMAQAG GMGVIHRNLT PVQQAEEVRQ VKKFESGMVV NPVTIGPDAT LAEALSLDEG
     PRHFRASPVV EKSHRLVGIL TNRDVRFASD PEQKIYELMT RENLVTVKDG VQQHEAKRLL
     HTHRIEKXLV VDADSRFVGL ITVKDIEKSQ LNPHASKDAQ GRLRAAAAIS VGDDGYERAE
     RLIDAGVDLL VVDTAHGHSQ RVLDAVTRVK KLSNSVRIMA GNVATYDGTR ALIDAGADAV
     KVGIGPGSIC TTRIVAGVGV PQLAAIMSAV QAAQDQNIPI IADGGIKFSG DLAKAIAAGA
     SAAMIGSLLA GTDESPGEVY LYQGRSFKAY RGMGSVGAMA RGSADRYFQA EVRDTLKLVP
     EGIEGXVPYK GPVSGVLHQL AGGLKAAMGY VGGADLKDFQ ERATFVRISG AGLRESHAHD
     VTITPRKARI IPAQAADR
//