ID A0A2K8SVG6_9NOSO Unreviewed; 331 AA.
AC A0A2K8SVG6;
DT 25-APR-2018, integrated into UniProtKB/TrEMBL.
DT 25-APR-2018, sequence version 1.
DT 24-JAN-2024, entry version 22.
DE RecName: Full=Ketol-acid reductoisomerase (NADP(+)) {ECO:0000256|HAMAP-Rule:MF_00435};
DE Short=KARI {ECO:0000256|HAMAP-Rule:MF_00435};
DE EC=1.1.1.86 {ECO:0000256|HAMAP-Rule:MF_00435};
DE AltName: Full=Acetohydroxy-acid isomeroreductase {ECO:0000256|HAMAP-Rule:MF_00435};
DE Short=AHIR {ECO:0000256|HAMAP-Rule:MF_00435};
DE AltName: Full=Alpha-keto-beta-hydroxylacyl reductoisomerase {ECO:0000256|HAMAP-Rule:MF_00435};
GN Name=ilvC {ECO:0000256|HAMAP-Rule:MF_00435};
GN ORFNames=COO91_05312 {ECO:0000313|EMBL:AUB39320.1};
OS Nostoc flagelliforme CCNUN1.
OC Bacteria; Cyanobacteriota; Cyanophyceae; Nostocales; Nostocaceae; Nostoc.
OX NCBI_TaxID=2038116 {ECO:0000313|EMBL:AUB39320.1, ECO:0000313|Proteomes:UP000232003};
RN [1] {ECO:0000313|EMBL:AUB39320.1, ECO:0000313|Proteomes:UP000232003}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCNUN1 {ECO:0000313|EMBL:AUB39320.1,
RC ECO:0000313|Proteomes:UP000232003};
RA Shang J.;
RT "Complete genome of a free-living desiccation-tolerant cyanobacterium and
RT its photosynthetic adaptation to extreme terrestrial habitat.";
RL Submitted (NOV-2017) 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:0000256|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:0000256|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:0000256|HAMAP-Rule:MF_00435};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00435};
CC Note=Binds 2 magnesium ions per subunit. {ECO:0000256|HAMAP-
CC Rule:MF_00435};
CC -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC isoleucine from 2-oxobutanoate: step 2/4.
CC {ECO:0000256|ARBA:ARBA00004885, ECO:0000256|HAMAP-Rule:MF_00435}.
CC -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC pyruvate: step 2/4. {ECO:0000256|ARBA:ARBA00004864, ECO:0000256|HAMAP-
CC Rule:MF_00435}.
CC -!- SIMILARITY: Belongs to the ketol-acid reductoisomerase family.
CC {ECO:0000256|ARBA:ARBA00010318, ECO:0000256|HAMAP-Rule:MF_00435,
CC ECO:0000256|PROSITE-ProRule:PRU01198}.
CC -!- CAUTION: Lacks conserved residue(s) required for the propagation of
CC feature annotation. {ECO:0000256|HAMAP-Rule:MF_00435}.
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DR EMBL; CP024785; AUB39320.1; -; Genomic_DNA.
DR AlphaFoldDB; A0A2K8SVG6; -.
DR KEGG; nfl:COO91_05312; -.
DR OrthoDB; 9804088at2; -.
DR UniPathway; UPA00047; UER00056.
DR UniPathway; UPA00049; UER00060.
DR Proteomes; UP000232003; Chromosome.
DR GO; GO:0016853; F:isomerase activity; IEA:UniProtKB-KW.
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; 2.
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 {ECO:0000256|ARBA:ARBA00022605, ECO:0000256|HAMAP-
KW Rule:MF_00435};
KW Branched-chain amino acid biosynthesis {ECO:0000256|ARBA:ARBA00023304,
KW ECO:0000256|HAMAP-Rule:MF_00435}; Isomerase {ECO:0000313|EMBL:AUB39320.1};
KW Magnesium {ECO:0000256|ARBA:ARBA00022842, ECO:0000256|HAMAP-Rule:MF_00435};
KW Metal-binding {ECO:0000256|ARBA:ARBA00022723, ECO:0000256|HAMAP-
KW Rule:MF_00435}; NADP {ECO:0000256|HAMAP-Rule:MF_00435};
KW Oxidoreductase {ECO:0000256|ARBA:ARBA00023002, ECO:0000256|HAMAP-
KW Rule:MF_00435}; Reference proteome {ECO:0000313|Proteomes:UP000232003}.
FT DOMAIN 2..182
FT /note="KARI N-terminal Rossmann"
FT /evidence="ECO:0000259|PROSITE:PS51850"
FT DOMAIN 183..328
FT /note="KARI C-terminal knotted"
FT /evidence="ECO:0000259|PROSITE:PS51851"
FT ACT_SITE 108
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435"
FT BINDING 25..28
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435"
FT BINDING 51
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435"
FT BINDING 53
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435"
FT BINDING 134
FT /ligand="NADP(+)"
FT /ligand_id="ChEBI:CHEBI:58349"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435"
FT BINDING 191
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
FT BINDING 191
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
FT BINDING 195
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
FT BINDING 227
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
FT BINDING 231
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
FT BINDING 252
FT /ligand="substrate"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00435,
FT ECO:0000256|PROSITE-ProRule:PRU01198"
SQ SEQUENCE 331 AA; 35891 MW; 33D21FA7C18E6AAC CRC64;
MARMYYDEDA NLDLLAGKTI AIIGYGSQGH AHALNLKDSG LNVIVGLYPG SKSVAKAEAA
GLTVKNVADA ANAADFIMIL LPDEVQKTIY KNEIEPNLEE GNVLAFAHGF NIHFGQVVPP
ANVDVVMVAP KGPGHLVRRT YEGGEGVPAL FAVYQDASGQ ARDRAMSYAK GIGGTRAGVL
ETTFREETET DLFGEQAVLC GGLSALIKAG FETLVEAGYQ PELAYFECLH EVKLIVDLVV
EGGLAKMRDS ISNTAEYGDY TRGPRIVTEQ TKAEMQKILS EIQSGQFARE FVLENQSGKP
GFTAMRRKEA EHKIEEVGKD LRAMFSWLKK A
//
