ID   ILVH_METJA              Reviewed;         172 AA.
AC   Q57625;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 118.
DE   RecName: Full=Probable acetolactate synthase small subunit;
DE            EC=2.2.1.6;
DE   AltName: Full=Acetohydroxy-acid synthase small subunit;
DE            Short=AHAS;
DE            Short=ALS;
GN   Name=ilvH; Synonyms=ilvN; OrderedLocusNames=MJ0161;
OS   Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM
OS   10045 / NBRC 100440) (Methanococcus jannaschii).
OC   Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC   Methanocaldococcaceae; Methanocaldococcus.
OX   NCBI_TaxID=243232;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440;
RX   PubMed=8688087; DOI=10.1126/science.273.5278.1058;
RA   Bult C.J., White O., Olsen G.J., Zhou L., Fleischmann R.D., Sutton G.G.,
RA   Blake J.A., FitzGerald L.M., Clayton R.A., Gocayne J.D., Kerlavage A.R.,
RA   Dougherty B.A., Tomb J.-F., Adams M.D., Reich C.I., Overbeek R.,
RA   Kirkness E.F., Weinstock K.G., Merrick J.M., Glodek A., Scott J.L.,
RA   Geoghagen N.S.M., Weidman J.F., Fuhrmann J.L., Nguyen D., Utterback T.R.,
RA   Kelley J.M., Peterson J.D., Sadow P.W., Hanna M.C., Cotton M.D.,
RA   Roberts K.M., Hurst M.A., Kaine B.P., Borodovsky M., Klenk H.-P.,
RA   Fraser C.M., Smith H.O., Woese C.R., Venter J.C.;
RT   "Complete genome sequence of the methanogenic archaeon, Methanococcus
RT   jannaschii.";
RL   Science 273:1058-1073(1996).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H(+) + 2 pyruvate = (2S)-2-acetolactate + CO2;
CC         Xref=Rhea:RHEA:25249, ChEBI:CHEBI:15361, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:16526, ChEBI:CHEBI:58476; EC=2.2.1.6;
CC   -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC       isoleucine from 2-oxobutanoate: step 1/4.
CC   -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC       pyruvate: step 1/4.
CC   -!- SUBUNIT: Dimer of large and small chains. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the acetolactate synthase small subunit family.
CC       {ECO:0000305}.
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DR   EMBL; L77117; AAB98145.1; -; Genomic_DNA.
DR   PIR; B64320; B64320.
DR   AlphaFoldDB; Q57625; -.
DR   SMR; Q57625; -.
DR   STRING; 243232.MJ_0161; -.
DR   EnsemblBacteria; AAB98145; AAB98145; MJ_0161.
DR   KEGG; mja:MJ_0161; -.
DR   eggNOG; arCOG04445; Archaea.
DR   HOGENOM; CLU_055003_1_3_2; -.
DR   InParanoid; Q57625; -.
DR   OMA; EPYGIKE; -.
DR   PhylomeDB; Q57625; -.
DR   UniPathway; UPA00047; UER00055.
DR   UniPathway; UPA00049; UER00059.
DR   Proteomes; UP000000805; Chromosome.
DR   GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR   GO; GO:0003984; F:acetolactate synthase activity; IBA:GO_Central.
DR   GO; GO:1990610; F:acetolactate synthase regulator activity; IEA:InterPro.
DR   GO; GO:0009097; P:isoleucine biosynthetic process; IBA:GO_Central.
DR   GO; GO:0009099; P:valine biosynthetic process; IBA:GO_Central.
DR   CDD; cd04878; ACT_AHAS; 1.
DR   Gene3D; 3.30.70.1150; -; 1.
DR   InterPro; IPR004789; Acetalactate_synth_ssu.
DR   InterPro; IPR027271; Acetolactate_synth/TF_NikR_C.
DR   InterPro; IPR019455; Acetolactate_synth_ssu_C.
DR   InterPro; IPR045865; ACT-like_dom_sf.
DR   InterPro; IPR002912; ACT_dom.
DR   InterPro; IPR039557; AHAS_ACT.
DR   PANTHER; PTHR30239; PTHR30239; 1.
DR   Pfam; PF10369; ALS_ss_C; 1.
DR   SUPFAM; SSF55021; SSF55021; 2.
DR   TIGRFAMs; TIGR00119; acolac_sm; 1.
DR   PROSITE; PS51671; ACT; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Branched-chain amino acid biosynthesis;
KW   Reference proteome; Transferase.
FT   CHAIN           1..172
FT                   /note="Probable acetolactate synthase small subunit"
FT                   /id="PRO_0000151423"
FT   DOMAIN          10..84
FT                   /note="ACT"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01007"
SQ   SEQUENCE   172 AA;  19057 MW;  8C00191BD2B18303 CRC64;
     MVNIMEHRHV ISALVLNKPG VLQRISGLFT RRGFNISSIT VGITENPQIS RVTIVVNGDD
     KILEQVIKQL NKLIDVIKVS ELEEKKSVQR ELCLIKIYAP TESAKSQVIQ YTSIFRGNVV
     DLSPESLIVE ITGSEDKINA FIDLVKPLGI KEMARTGITA LARGPKILKP KS