AC MF_00435; DC Protein; auto TR HAMAP; MF_00435; -; 1; level=0 XX Names: IlvC XX ID ILVC DE RecName: Full=Ketol-acid reductoisomerase (NADP(+)); DE Short=KARI; DE EC=1.1.1.86; DE AltName: Full=Acetohydroxy-acid isomeroreductase; DE Short=AHIR; DE AltName: Full=Alpha-keto-beta-hydroxylacyl reductoisomerase; case DE AltName: Full=Ketol-acid reductoisomerase type 1; DE AltName: Full=Ketol-acid reductoisomerase type I; else case DE AltName: Full=Ketol-acid reductoisomerase type 2; DE AltName: Full=Ketol-acid reductoisomerase type II; end case GN Name=ilvC; XX CC -!- FUNCTION: Involved in the biosynthesis of branched-chain amino acids CC (BCAA). Catalyzes an alkyl-migration followed by a ketol-acid reduction CC of (S)-2-acetolactate (S2AL) to yield (R)-2,3-dihydroxy-isovalerate. In CC the isomerase reaction, S2AL is rearranged via a Mg-dependent methyl CC migration to produce 3-hydroxy-3-methyl-2-ketobutyrate (HMKB). In the CC reductase reaction, this 2-ketoacid undergoes a metal-dependent CC reduction by NADPH to yield (R)-2,3-dihydroxy-isovalerate. CC -!- CATALYTIC ACTIVITY: CC Reaction=(2R)-2,3-dihydroxy-3-methylbutanoate + NADP(+) = (2S)-2- CC acetolactate + H(+) + NADPH; Xref=Rhea:RHEA:22068, ChEBI:CHEBI:15378, CC ChEBI:CHEBI:49072, ChEBI:CHEBI:57783, ChEBI:CHEBI:58349, CC ChEBI:CHEBI:58476; EC=1.1.1.86; CC -!- CATALYTIC ACTIVITY: CC Reaction=(2R,3R)-2,3-dihydroxy-3-methylpentanoate + NADP(+) = (S)-2- CC ethyl-2-hydroxy-3-oxobutanoate + H(+) + NADPH; Xref=Rhea:RHEA:13493, CC ChEBI:CHEBI:15378, ChEBI:CHEBI:49256, ChEBI:CHEBI:49258, CC ChEBI:CHEBI:57783, ChEBI:CHEBI:58349; EC=1.1.1.86; CC -!- COFACTOR: CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420; CC Note=Binds 2 magnesium ions per subunit CC -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L- CC isoleucine from 2-oxobutanoate: step 2/4. CC -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from CC pyruvate: step 2/4. CC -!- SIMILARITY: Belongs to the ketol-acid reductoisomerase family. XX DR Pfam; PF01450; IlvC; 1-2; trigger=no DR Pfam; PF07991; IlvN; 1; trigger=no DR NCBIfam; TIGR00465; IlvC; 1; trigger=no DR PROSITE; PS51851; KARI_C; 1-2; trigger=yes DR PROSITE; PS51850; KARI_N; 1; trigger=yes XX KW Oxidoreductase KW Amino-acid biosynthesis KW Branched-chain amino acid biosynthesis KW Magnesium KW Metal-binding KW NADP case KW Repeat end case XX GO GO:0000287; F:magnesium ion binding GO GO:0004455; F:ketol-acid reductoisomerase activity GO GO:0009097; P:isoleucine biosynthetic process GO GO:0009099; P:valine biosynthetic process XX FT From: ILVC_ECOLI (P05793) FT BINDING 45..48 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: [CYF]-G-x-Q FT BINDING 108..110 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: D-x(1,2)-Q FT ACT_SITE 132 FT Condition: H FT BINDING 217 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="1" FT Condition: D FT BINDING 217 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT Condition: D FT BINDING 221 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="1" FT Condition: E FT BINDING 389 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT Condition: E FT BINDING 393 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT Condition: E FT BINDING 68 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: [RK] FT BINDING 76 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: [RS] FT BINDING 78 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: [ST] FT BINDING 158 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT Optional; Condition: G FT BINDING 414 FT /ligand="substrate" FT Condition: S XX Size: 326-494; Related: None; Template: P05793; Q57179; P05989; D0WGK0; K4LVZ1; Q0AV19; B4U6I9; C1DFH7; C8WR67; Q02138; P9WKJ7; E0SRA9; O28294; A4YI15; Q64BR7; Scope: Bacteria Archaea Fusion: Nter: None Cter: None Duplicate: in BACAN, BACC1, BACCR, BACCZ, BACHK, BIFLO, STRCO, SACS2 Plasmid: None Comments: Two additional divergent sequences in SACS2 (SSO1322 and SSO1942) not shown in alignment. Enterobacteria have a duplication of the KARI_C domain. XX # Revision 1.39 2023/06/01 //