ID   ILVC3_SACS2             Reviewed;         332 AA.
AC   Q97X13;
DT   29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT   29-AUG-2001, sequence version 1.
DT   25-MAY-2022, entry version 118.
DE   RecName: Full=Putative ketol-acid reductoisomerase 3;
DE            EC=1.1.1.86;
DE   AltName: Full=Acetohydroxy-acid isomeroreductase 3;
DE   AltName: Full=Alpha-keto-beta-hydroxylacyl reductoisomerase 3;
GN   Name=ilvC3; Synonyms=ilvC-3; OrderedLocusNames=SSO1942;
OS   Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)
OS   (Sulfolobus solfataricus).
OC   Archaea; Crenarchaeota; Thermoprotei; Sulfolobales; Sulfolobaceae;
OC   Saccharolobus.
OX   NCBI_TaxID=273057;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35092 / DSM 1617 / JCM 11322 / P2;
RX   PubMed=11427726; DOI=10.1073/pnas.141222098;
RA   She Q., Singh R.K., Confalonieri F., Zivanovic Y., Allard G., Awayez M.J.,
RA   Chan-Weiher C.C.-Y., Clausen I.G., Curtis B.A., De Moors A., Erauso G.,
RA   Fletcher C., Gordon P.M.K., Heikamp-de Jong I., Jeffries A.C., Kozera C.J.,
RA   Medina N., Peng X., Thi-Ngoc H.P., Redder P., Schenk M.E., Theriault C.,
RA   Tolstrup N., Charlebois R.L., Doolittle W.F., Duguet M., Gaasterland T.,
RA   Garrett R.A., Ragan M.A., Sensen C.W., Van der Oost J.;
RT   "The complete genome of the crenarchaeon Sulfolobus solfataricus P2.";
RL   Proc. Natl. Acad. Sci. U.S.A. 98:7835-7840(2001).
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   -!- 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   -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC       isoleucine from 2-oxobutanoate: step 2/4.
CC   -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC       pyruvate: step 2/4.
CC   -!- SIMILARITY: Belongs to the ketol-acid reductoisomerase family.
CC       {ECO:0000305}.
CC   -!- CAUTION: Ser-107 is present instead of the conserved His which is
CC       expected to be an active site residue. {ECO:0000305}.
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DR   EMBL; AE006641; AAK42136.1; -; Genomic_DNA.
DR   PIR; A90360; A90360.
DR   RefSeq; WP_009992598.1; NC_002754.1.
DR   AlphaFoldDB; Q97X13; -.
DR   SMR; Q97X13; -.
DR   STRING; 273057.SSO1942; -.
DR   EnsemblBacteria; AAK42136; AAK42136; SSO1942.
DR   GeneID; 44130735; -.
DR   KEGG; sso:SSO1942; -.
DR   PATRIC; fig|273057.12.peg.2016; -.
DR   eggNOG; arCOG04465; Archaea.
DR   HOGENOM; CLU_033821_0_0_2; -.
DR   InParanoid; Q97X13; -.
DR   OMA; REETAMD; -.
DR   PhylomeDB; Q97X13; -.
DR   UniPathway; UPA00047; UER00056.
DR   UniPathway; UPA00049; UER00060.
DR   Proteomes; UP000001974; Chromosome.
DR   GO; GO:0004455; F:ketol-acid reductoisomerase activity; IBA:GO_Central.
DR   GO; GO:0009097; P:isoleucine biosynthetic process; IBA:GO_Central.
DR   GO; GO:0009099; P:valine biosynthetic process; IBA:GO_Central.
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; IPR036291; NAD(P)-bd_dom_sf.
DR   PANTHER; PTHR21371; PTHR21371; 1.
DR   Pfam; PF01450; IlvC; 1.
DR   Pfam; PF07991; IlvN; 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; NADP;
KW   Oxidoreductase; Reference proteome.
FT   CHAIN           1..332
FT                   /note="Putative ketol-acid reductoisomerase 3"
FT                   /id="PRO_0000151402"
FT   DOMAIN          1..182
FT                   /note="KARI N-terminal Rossmann"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01197"
FT   DOMAIN          183..329
FT                   /note="KARI C-terminal knotted"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01198"
SQ   SEQUENCE   332 AA;  37071 MW;  E4861E33EAC6AF22 CRC64;
     MDKTVLDASL EPLKGKTIAV IGYGNQGRVQ ANIMRENGLN VIIGNVKDRY YDLAIKEGFE
     VYDIGEAVKK ADVAFLLIPD EIMKEIYEKK IAPILEGKKE FVLDFASGYN VAFGLIRPPK
     NVDTVMVAPR MVGEGIMDLH KQGKGYPVLL GVKQDASGKA WDYAKAIAKG IGAIPGGIAV
     ISSFEEEALL DLMSEHTWVP ILFGAIKACF DVAVKEYGVS PEAALLEFYA SGELVEIARL
     IAEEGIFNQM VHHSTTSQYG TLTRMFKYYD LVKEIVKDEA KYIWDGSFAK EWTLEQQAGY
     PVFYRLWELA VQSEMAKAEK ELYKILRRKV SD