ILVC_STRT1
ID ILVC_STRT1 Reviewed; 340 AA.
AC Q5LXV0;
DT 07-MAR-2006, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-2005, sequence version 1.
DT 03-AUG-2022, entry version 100.
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}; OrderedLocusNames=str1871;
OS Streptococcus thermophilus (strain CNRZ 1066).
OC Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC Streptococcus.
OX NCBI_TaxID=299768;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CNRZ 1066;
RX PubMed=15543133; DOI=10.1038/nbt1034;
RA Bolotin A., Quinquis B., Renault P., Sorokin A., Ehrlich S.D.,
RA Kulakauskas S., Lapidus A., Goltsman E., Mazur M., Pusch G.D., Fonstein M.,
RA Overbeek R., Kyprides N., Purnelle B., Prozzi D., Ngui K., Masuy D.,
RA Hancy F., Burteau S., Boutry M., Delcour J., Goffeau A., Hols P.;
RT "Complete sequence and comparative genome analysis of the dairy bacterium
RT Streptococcus thermophilus.";
RL Nat. Biotechnol. 22:1554-1558(2004).
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; CP000024; AAV63385.1; -; Genomic_DNA.
DR RefSeq; WP_011226634.1; NC_006449.1.
DR AlphaFoldDB; Q5LXV0; -.
DR SMR; Q5LXV0; -.
DR GeneID; 66899603; -.
DR KEGG; stc:str1871; -.
DR HOGENOM; CLU_033821_0_1_9; -.
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_0000226206"
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; 37401 MW; A284F41C1C1C9C6B 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 VKENMKAVLT DIQNGKFAND FVNDYKAGRP
KLTAYREEAA NLEIEKVGAE LRKAMPFVGQ NDDDAFKIYN
