ID   ILVH_LACLA              Reviewed;         158 AA.
AC   Q02140; Q9CG83;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   26-SEP-2001, sequence version 2.
DT   03-AUG-2022, entry version 124.
DE   RecName: Full=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=LL1225; ORFNames=L0079;
OS   Lactococcus lactis subsp. lactis (strain IL1403) (Streptococcus lactis).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC   Lactococcus.
OX   NCBI_TaxID=272623;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=NCDO 2118;
RX   PubMed=1400210; DOI=10.1128/jb.174.20.6580-6589.1992;
RA   Godon J.-J., Chopin M.-C., Ehrlich S.D.;
RT   "Branched-chain amino acid biosynthesis genes in Lactococcus lactis subsp.
RT   lactis.";
RL   J. Bacteriol. 174:6580-6589(1992).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=IL1403;
RX   PubMed=11337471; DOI=10.1101/gr.gr-1697r;
RA   Bolotin A., Wincker P., Mauger S., Jaillon O., Malarme K., Weissenbach J.,
RA   Ehrlich S.D., Sorokin A.;
RT   "The complete genome sequence of the lactic acid bacterium Lactococcus
RT   lactis ssp. lactis IL1403.";
RL   Genome Res. 11:731-753(2001).
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; U92974; AAB81920.1; -; Genomic_DNA.
DR   EMBL; AE005176; AAK05323.1; -; Genomic_DNA.
DR   PIR; A86778; A86778.
DR   PIR; S35139; S35139.
DR   RefSeq; NP_267381.1; NC_002662.1.
DR   RefSeq; WP_010905839.1; NC_002662.1.
DR   AlphaFoldDB; Q02140; -.
DR   SMR; Q02140; -.
DR   STRING; 272623.L0079; -.
DR   PaxDb; Q02140; -.
DR   EnsemblBacteria; AAK05323; AAK05323; L0079.
DR   GeneID; 60354981; -.
DR   KEGG; lla:L0079; -.
DR   PATRIC; fig|272623.7.peg.1324; -.
DR   eggNOG; COG0440; Bacteria.
DR   HOGENOM; CLU_055003_4_0_9; -.
DR   OMA; EPYGIKE; -.
DR   UniPathway; UPA00047; UER00055.
DR   UniPathway; UPA00049; UER00059.
DR   Proteomes; UP000002196; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProt.
DR   GO; GO:0003984; F:acetolactate synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:1990610; F:acetolactate synthase regulator activity; IEA:InterPro.
DR   GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniPathway.
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; PF01842; ACT; 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..158
FT                   /note="Acetolactate synthase small subunit"
FT                   /id="PRO_0000151413"
FT   DOMAIN          4..79
FT                   /note="ACT"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01007"
FT   CONFLICT        80
FT                   /note="L -> F (in Ref. 1; AAB81920)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        137
FT                   /note="D -> E (in Ref. 1; AAB81920)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   158 AA;  17641 MW;  9A9D29AA5291A087 CRC64;
     MRRMIIAKLH NVTGIMNRFT AVLNRRQVNI LSITAGVTES QDLTHTTFVI EVDHLDEVEQ
     IIKQLNRLID VIEVADITDL PHVEREVVLI KVSAPPTIRA EIFTMIEPFR VNVVDVNLEN
     VTIQLTGDSA KIEALIDVVS PYGILNMART GSAGFERG