ILVC_BUCUN
ID ILVC_BUCUN Reviewed; 345 AA.
AC Q9AQ99;
DT 29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2001, sequence version 1.
DT 03-AUG-2022, entry version 91.
DE RecName: Full=Ketol-acid reductoisomerase (NADP(+)) {ECO:0000250|UniProtKB:P05793};
DE Short=KARI {ECO:0000250|UniProtKB:P05793};
DE EC=1.1.1.86 {ECO:0000250|UniProtKB:P05793};
DE AltName: Full=Acetohydroxy-acid isomeroreductase {ECO:0000250|UniProtKB:P05793};
DE Short=AHIR {ECO:0000250|UniProtKB:P05793};
DE AltName: Full=Alpha-keto-beta-hydroxylacyl reductoisomerase {ECO:0000250|UniProtKB:P05793};
DE AltName: Full=Ketol-acid reductoisomerase type 2 {ECO:0000250|UniProtKB:P05793};
DE AltName: Full=Ketol-acid reductoisomerase type II {ECO:0000250|UniProtKB:P05793};
DE Flags: Fragment;
GN Name=ilvC;
OS Buchnera aphidicola subsp. Uroleucon sonchi.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=118118;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA Wernegreen J.J., Moran N.A.;
RT "Accelerated evolutionary rates at biosynthetic loci of Buchnera-
RT Uroleucon.";
RL Submitted (DEC-1999) to the EMBL/GenBank/DDBJ databases.
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:0000250|UniProtKB:P05793}.
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 Evidence={ECO:0000250|UniProtKB:P05793};
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:0000250|UniProtKB:P05793};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P05793};
CC Note=Binds 2 magnesium ions per subunit.
CC {ECO:0000250|UniProtKB:P05793};
CC -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC isoleucine from 2-oxobutanoate: step 2/4.
CC {ECO:0000250|UniProtKB:P05793}.
CC -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC pyruvate: step 2/4. {ECO:0000250|UniProtKB:P05793}.
CC -!- SIMILARITY: Belongs to the ketol-acid reductoisomerase family.
CC {ECO:0000305}.
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DR EMBL; AF217554; AAK01025.1; -; Genomic_DNA.
DR AlphaFoldDB; Q9AQ99; -.
DR SMR; Q9AQ99; -.
DR UniPathway; UPA00047; UER00056.
DR UniPathway; UPA00049; UER00060.
DR GO; GO:0004455; F:ketol-acid reductoisomerase activity; IEA:UniProtKB-EC.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0050661; F:NADP binding; IEA:InterPro.
DR GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniPathway.
DR GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniPathway.
DR Gene3D; 1.10.1040.10; -; 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; IPR014359; KARI_prok.
DR InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR PANTHER; PTHR21371; PTHR21371; 2.
DR Pfam; PF01450; IlvC; 1.
DR Pfam; PF07991; IlvN; 1.
DR PIRSF; PIRSF000116; IlvC_gammaproteo; 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..>345
FT /note="Ketol-acid reductoisomerase (NADP(+))"
FT /id="PRO_0000151296"
FT DOMAIN <1..141
FT /note="KARI N-terminal Rossmann"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01197"
FT DOMAIN 142..286
FT /note="KARI C-terminal knotted 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT DOMAIN 287..>345
FT /note="KARI C-terminal knotted 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT ACT_SITE 65
FT /evidence="ECO:0000250|UniProtKB:P05793"
FT BINDING 11
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000250|UniProtKB:P05793"
FT BINDING 41..43
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000250|UniProtKB:P05793"
FT BINDING 91
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000250|UniProtKB:P05793"
FT BINDING 150
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT BINDING 150
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT BINDING 154
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT BINDING 322
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT BINDING 326
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT NON_TER 1
FT NON_TER 345
SQ SEQUENCE 345 AA; 39244 MW; 6FE05ABA7849DD03 CRC64;
KKNSIAKKNQ SWINAIENNF KVDDYESLIP NADLVINLTP DKEHHHVVQV LQKLMKKNSC
LGYSHGFNIV EFGEIIRKDI TVIMVAPKCP GTEVREEYKR GFGVPTLIAV HNENDIRQIG
LDIAKAWSFS IGSHRAGVLE SSFIAEVKSD LMGEQTILCG MLQTASLLCY EKLIANKNDP
AYASKLIQNG WETITESLKH GGITLMMDRL SNASKIRAYN ISEKIKKILS SLFQKHMNDI
ISGEFSHKMM QDWQNNNKQL LDWRNKNKNT SFEKAPVYHN KIPEQEYYDH GILMIAILKA
GIELSFETML NSGIIAESAY YESLHELPLI ANTIARKKLY EMNKV
