ILVC_BUCSC
ID ILVC_BUCSC Reviewed; 489 AA.
AC Q9RQ51;
DT 29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 03-AUG-2022, entry version 102.
DE RecName: Full=Ketol-acid reductoisomerase (NADP(+)) {ECO:0000255|HAMAP-Rule:MF_00435};
DE Short=KARI {ECO:0000255|HAMAP-Rule:MF_00435};
DE EC=1.1.1.86 {ECO:0000255|HAMAP-Rule:MF_00435};
DE AltName: Full=Acetohydroxy-acid isomeroreductase {ECO:0000255|HAMAP-Rule:MF_00435};
DE Short=AHIR {ECO:0000255|HAMAP-Rule:MF_00435};
DE AltName: Full=Alpha-keto-beta-hydroxylacyl reductoisomerase {ECO:0000255|HAMAP-Rule:MF_00435};
DE AltName: Full=Ketol-acid reductoisomerase type 2 {ECO:0000255|HAMAP-Rule:MF_00435};
DE AltName: Full=Ketol-acid reductoisomerase type II {ECO:0000255|HAMAP-Rule:MF_00435};
GN Name=ilvC {ECO:0000255|HAMAP-Rule:MF_00435};
OS Buchnera aphidicola subsp. Schlechtendalia chinensis.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=118110;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=10555290; DOI=10.1093/oxfordjournals.molbev.a026071;
RA Clark M.A., Moran N.A., Baumann P.;
RT "Sequence evolution in bacterial endosymbionts having extreme base
RT compositions.";
RL Mol. Biol. Evol. 16:1586-1598(1999).
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 {ECO:0000255|HAMAP-Rule:MF_00435}.
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; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_00435};
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 Evidence={ECO:0000255|HAMAP-Rule:MF_00435};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00435};
CC Note=Binds 2 magnesium ions per subunit. {ECO:0000255|HAMAP-
CC Rule:MF_00435};
CC -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC isoleucine from 2-oxobutanoate: step 2/4. {ECO:0000255|HAMAP-
CC Rule:MF_00435}.
CC -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC pyruvate: step 2/4. {ECO:0000255|HAMAP-Rule:MF_00435}.
CC -!- SIMILARITY: Belongs to the ketol-acid reductoisomerase family.
CC {ECO:0000255|HAMAP-Rule:MF_00435}.
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DR EMBL; AF130813; AAF13803.1; -; Genomic_DNA.
DR AlphaFoldDB; Q9RQ51; -.
DR SMR; Q9RQ51; -.
DR STRING; 118110.XW81_02775; -.
DR PRIDE; Q9RQ51; -.
DR UniPathway; UPA00047; UER00056.
DR UniPathway; UPA00049; UER00060.
DR GO; GO:0004455; F:ketol-acid reductoisomerase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniRule.
DR GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniRule.
DR Gene3D; 1.10.1040.10; -; 1.
DR HAMAP; MF_00435; IlvC; 1.
DR InterPro; IPR008927; 6-PGluconate_DH-like_C_sf.
DR InterPro; IPR013328; 6PGD_dom2.
DR InterPro; IPR013023; KARI.
DR InterPro; IPR000506; KARI_C.
DR InterPro; IPR013116; KARI_N.
DR InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR PANTHER; PTHR21371; PTHR21371; 2.
DR Pfam; PF01450; IlvC; 2.
DR Pfam; PF07991; IlvN; 1.
DR SUPFAM; SSF48179; SSF48179; 2.
DR SUPFAM; SSF51735; SSF51735; 1.
DR TIGRFAMs; TIGR00465; ilvC; 1.
DR PROSITE; PS51851; KARI_C; 2.
DR PROSITE; PS51850; KARI_N; 1.
PE 3: Inferred from homology;
KW Amino-acid biosynthesis; Branched-chain amino acid biosynthesis; Magnesium;
KW Metal-binding; NADP; Oxidoreductase; Repeat.
FT CHAIN 1..489
FT /note="Ketol-acid reductoisomerase (NADP(+))"
FT /id="PRO_0000151292"
FT DOMAIN 16..207
FT /note="KARI N-terminal Rossmann"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01197"
FT DOMAIN 208..343
FT /note="KARI C-terminal knotted 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT DOMAIN 344..483
FT /note="KARI C-terminal knotted 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT ACT_SITE 131
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 44..47
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 67
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 77
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 107..109
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 157
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 216
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 216
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 220
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 388
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 392
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 413
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
SQ SEQUENCE 489 AA; 55710 MW; BFB94B15F507641F CRC64;
MNYFNSLNFR QKLINLRKCK LVEKNFFSKK CDILKRKNIV IVGCGSQGLN QGLNMRDSGL
HVSYALRGSS ILNKNKSWEN ATKNNFFVDT YENIIPTADL VINLTPDKQR KEVVTLLQKF
MKENSVLGFS HGFHIVEIGQ KIRNDITVIM VAPKCPGTEV REEYKKGFGV PSLIAVHMEN
DPKKIGFEIA KAWAYSLGSH RAGVLHSSFI AEVKSDLMGE QTILCGMLQT SSLVCYDQLV
SQGKDPNYAG KLIQLGWESI TESVKHGGIT LMLNRLSNTA KIRAYILSKK LKVMFSSLFR
KHMDDIISGE FSKNMIDDWN SDDKKLKEWR TQIKKTDFEK CKICHKEISE QEYFDQGLLM
VAILKAGIEL SFEIMVETGI KEESAYYESL HELPLIANTI ARKRLYEMNL VISDTAEYGS
YLFSQSAIPL LKEFMNELCP GDLGEKISDL QFDNVTLNKI NHDIENHPVE IIGKKLRKYM
VDMKPIKLS
