ILVC_STRTR
ID ILVC_STRTR Reviewed; 340 AA.
AC Q9F0I7;
DT 29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2001, sequence version 1.
DT 03-AUG-2022, entry version 107.
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 1 {ECO:0000255|HAMAP-Rule:MF_00435};
DE AltName: Full=Ketol-acid reductoisomerase type I {ECO:0000255|HAMAP-Rule:MF_00435};
GN Name=ilvC {ECO:0000255|HAMAP-Rule:MF_00435};
OS Streptococcus thermophilus.
OC Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC Streptococcus.
OX NCBI_TaxID=1308;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ST18;
RX PubMed=11097879; DOI=10.1128/aem.66.12.5128-5133.2000;
RA Garault P., Letort C., Juillard V., Monnet V.;
RT "Branched-chain amino acid biosynthesis is essential for optimal growth of
RT Streptococcus thermophilus in milk.";
RL Appl. Environ. Microbiol. 66:5128-5133(2000).
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; AF220670; AAG39032.1; -; Genomic_DNA.
DR RefSeq; WP_002952054.1; NZ_WMLD01000010.1.
DR AlphaFoldDB; Q9F0I7; -.
DR SMR; Q9F0I7; -.
DR STRING; 322159.STER_1848; -.
DR eggNOG; COG0059; Bacteria.
DR OMA; RAMFSWL; -.
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:0050661; F:NADP binding; IEA:InterPro.
DR GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniRule.
DR GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniRule.
DR HAMAP; MF_00435; IlvC; 1.
DR InterPro; IPR008927; 6-PGluconate_DH-like_C_sf.
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; 1.
DR Pfam; PF01450; IlvC; 1.
DR Pfam; PF07991; IlvN; 1.
DR PIRSF; PIRSF000116; IlvC_gammaproteo; 1.
DR SUPFAM; SSF48179; SSF48179; 1.
DR SUPFAM; SSF51735; SSF51735; 1.
DR TIGRFAMs; TIGR00465; ilvC; 1.
DR PROSITE; PS51851; KARI_C; 1.
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.
FT CHAIN 1..340
FT /note="Ketol-acid reductoisomerase (NADP(+))"
FT /id="PRO_0000151369"
FT DOMAIN 3..182
FT /note="KARI N-terminal Rossmann"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01197"
FT DOMAIN 183..328
FT /note="KARI C-terminal knotted"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
FT ACT_SITE 108
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 26..29
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 49
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 53
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 83..86
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 134
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 191
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 191
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 195
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 227
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 231
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 252
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
SQ SEQUENCE 340 AA; 37371 MW; BEF4F41C09099C7E CRC64;
MAVQMEYEKD VKVPALDGKK IAVIGYGSQG HAHSQNLRDT GHDVIIGVRP GKSFDKAKED
GFDTYTVAEA TKLADVIMIL APDEIQQELY EAEIAPNLEA GNAVGFAHGF NIHFEFIKVP
ADVDVFMCAP KGPGHLVRRT FEEGFGVPAL YAVYQDATGN AKDIAMDWCK GIGAARVGLL
ETTYKEETEE DLFGEQAVLC GGLTALIETG FEVLTEAGYA PELAYFEVLH EMKLIVDLIY
EGGFKKMRQS ISNTAEFGDY VSGPRVITEQ VKENMKAVLA DIQNGKFAND FVNDYKAGRP
KLTAYREEAA NLEIEKVGAE LRKAMPFVGQ NDDDAFKIYN
