ID ILVC_SYNS3 Reviewed; 331 AA.
AC Q0IC80;
DT 15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT 03-OCT-2006, sequence version 1.
DT 27-MAR-2024, entry version 109.
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=sync_0725;
OS Synechococcus sp. (strain CC9311).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales; Synechococcaceae;
OC Synechococcus.
OX NCBI_TaxID=64471;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CC9311;
RX PubMed=16938853; DOI=10.1073/pnas.0602963103;
RA Palenik B., Ren Q., Dupont C.L., Myers G.S., Heidelberg J.F., Badger J.H.,
RA Madupu R., Nelson W.C., Brinkac L.M., Dodson R.J., Durkin A.S.,
RA Daugherty S.C., Sullivan S.A., Khouri H., Mohamoud Y., Halpin R.,
RA Paulsen I.T.;
RT "Genome sequence of Synechococcus CC9311: insights into adaptation to a
RT coastal environment.";
RL Proc. Natl. Acad. Sci. U.S.A. 103:13555-13559(2006).
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; CP000435; ABI45803.1; -; Genomic_DNA.
DR RefSeq; WP_011618669.1; NC_008319.1.
DR AlphaFoldDB; Q0IC80; -.
DR SMR; Q0IC80; -.
DR STRING; 64471.sync_0725; -.
DR KEGG; syg:sync_0725; -.
DR eggNOG; COG0059; Bacteria.
DR HOGENOM; CLU_033821_0_1_3; -.
DR OrthoDB; 9804088at2; -.
DR UniPathway; UPA00047; UER00056.
DR UniPathway; UPA00049; UER00060.
DR Proteomes; UP000001961; Chromosome.
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 Gene3D; 6.10.240.10; -; 1.
DR Gene3D; 3.40.50.720; NAD(P)-binding Rossmann-like Domain; 1.
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 NCBIfam; TIGR00465; ilvC; 1.
DR PANTHER; PTHR21371; KETOL-ACID REDUCTOISOMERASE, MITOCHONDRIAL; 1.
DR PANTHER; PTHR21371:SF1; KETOL-ACID REDUCTOISOMERASE, MITOCHONDRIAL; 1.
DR Pfam; PF01450; IlvC; 1.
DR Pfam; PF07991; IlvN; 1.
DR PIRSF; PIRSF000116; IlvC_gammaproteo; 1.
DR SUPFAM; SSF48179; 6-phosphogluconate dehydrogenase C-terminal domain-like; 1.
DR SUPFAM; SSF51735; NAD(P)-binding Rossmann-fold domains; 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; Reference proteome.
FT CHAIN 1..331
FT /note="Ketol-acid reductoisomerase (NADP(+))"
FT /id="PRO_1000050585"
FT DOMAIN 2..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 25..28
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00435"
FT BINDING 51
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 331 AA; 35579 MW; 886A14FFA21970BF CRC64;
MAQLFYDSDA DLSLLSGKTV AIIGYGSQGH AHALNLKDSG VNVVVGLYAG SRSAEKAKAD
GLEVLSVADA SAKADWIMVL LPDEFQKEVY EKEIAPHLSA GKVLSFAHGF NIRFELIKPP
ADVDVLMIAP KGPGHTVRWE YQNGQGVPAL FAIEQDASGN ARGLAMAYAK GIGGTRAGIL
ETNFKEETET DLFGEQAVLC GGLSELVKAG FETLVEAGYQ PELAYFECLH EVKLIVDLMV
KGGLSSMRDS ISNTAEYGDY VSGPRLITAD TKAEMKRILS DIQDGTFAKN FVAECAAGKP
EMNKVRARDA EHPIEKVGKG LRSMFSWLKA A
//
