AC MF_01964; DC Protein; auto c? or TR HAMAP; MF_01964; -; 1; level=0 XX Names: IMPDH XX ID IMDH DE RecName: Full=Inosine-5'-monophosphate dehydrogenase; DE Short=IMP dehydrogenase; DE Short=IMPD; DE Short=IMPDH; DE EC=1.1.1.205; GN Name=guaB; XX 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 -!- 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; CC -!- COFACTOR: CC Name=K(+); Xref=ChEBI:CHEBI:29103; 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. CC -!- PATHWAY: Purine metabolism; XMP biosynthesis via de novo pathway; XMP CC from IMP: step 1/1. CC -!- SUBUNIT: Homotetramer. CC -!- SIMILARITY: Belongs to the IMPDH/GMPR family. XX DR PROSITE; PS51371; CBS; 0-2; trigger=yes DR PROSITE; PS00487; IMP_DH_GMP_RED; 1; trigger=no DR Pfam; PF00571; CBS; 2; trigger=no DR Pfam; PF00478; IMPDH; 1; trigger=no DR NCBIfam; TIGR01302; IMP_dehydrog; 1; trigger=no DR PIRSF; PIRSF000130; IMPDH; 1; trigger=no XX KW GMP biosynthesis KW Metal-binding KW NAD KW Oxidoreductase KW Potassium KW Purine biosynthesis XX GO GO:0003938; F:IMP dehydrogenase activity GO GO:0046872; F:metal ion binding GO GO:0000166; F:nucleotide binding GO GO:0006177; P:GMP biosynthetic process XX FT From: IMDH_TRIFO (P50097) FT BINDING 261..263 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT Optional; Condition: D-S-S case not FT BINDING 261 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT Optional; Condition: D end case FT BINDING 312..314 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT Condition: G-x-G FT BINDING 358..360 FT /ligand="IMP" FT /ligand_id="ChEBI:CHEBI:58053" FT Condition: D-G-G FT BINDING 381..382 FT /ligand="IMP" FT /ligand_id="ChEBI:CHEBI:58053" FT Condition: G-x FT BINDING 405..409 FT /ligand="IMP" FT /ligand_id="ChEBI:CHEBI:58053" FT Condition: [YI]-x-x-x-[GA] FT ACT_SITE 319 FT /note="Thioimidate intermediate" FT Condition: C FT ACT_SITE 418 FT /note="Proton acceptor" FT Condition: R FT BINDING 314 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 Condition: G FT BINDING 316 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 Condition: G FT BINDING 319 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 Condition: C FT BINDING 485 FT /ligand="K(+)" FT /ligand_id="ChEBI:CHEBI:29103" FT /ligand_note="ligand shared between two tetrameric FT partners" FT Optional; Condition: E FT BINDING 486 FT /ligand="K(+)" FT /ligand_id="ChEBI:CHEBI:29103" FT /ligand_note="ligand shared between two tetrameric FT partners" FT Optional; Condition: [GS] FT BINDING 487 FT /ligand="K(+)" FT /ligand_id="ChEBI:CHEBI:29103" FT /ligand_note="ligand shared between two tetrameric FT partners" FT Optional; Condition: [GH] FT BINDING 317 FT /ligand="IMP" FT /ligand_id="ChEBI:CHEBI:58053" FT Condition: S FT BINDING 431 FT /ligand="IMP" FT /ligand_id="ChEBI:CHEBI:58053" FT Condition: [EQ] XX Size: 400-554; Related: None; Template: P50097; P0C0H6; P49058; P0ADG7; P9WKI7; Scope: Archaea Bacteria Fusion: Nter: None Cter: None Duplicate: None Plasmid: in BORBU Comments: None XX # Revision 1.15 2023/06/01 //