ID   A4SXR4_POLAQ            Unreviewed;       163 AA.
AC   A4SXR4;
DT   15-MAY-2007, integrated into UniProtKB/TrEMBL.
DT   15-MAY-2007, sequence version 1.
DT   27-MAR-2024, entry version 86.
DE   RecName: Full=Acetolactate synthase small subunit {ECO:0000256|RuleBase:RU368092};
DE            Short=AHAS {ECO:0000256|RuleBase:RU368092};
DE            Short=ALS {ECO:0000256|RuleBase:RU368092};
DE            EC=2.2.1.6 {ECO:0000256|RuleBase:RU368092};
DE   AltName: Full=Acetohydroxy-acid synthase small subunit {ECO:0000256|RuleBase:RU368092};
GN   OrderedLocusNames=Pnuc_1062 {ECO:0000313|EMBL:ABP34278.1};
OS   Polynucleobacter asymbioticus (strain DSM 18221 / CIP 109841 /
OS   QLW-P1DMWA-1) (Polynucleobacter necessarius subsp. asymbioticus).
OC   Bacteria; Pseudomonadota; Betaproteobacteria; Burkholderiales;
OC   Burkholderiaceae; Polynucleobacter.
OX   NCBI_TaxID=312153 {ECO:0000313|EMBL:ABP34278.1, ECO:0000313|Proteomes:UP000000231};
RN   [1] {ECO:0000313|EMBL:ABP34278.1, ECO:0000313|Proteomes:UP000000231}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 18221 / CIP 109841 / QLW-P1DMWA-1
RC   {ECO:0000313|Proteomes:UP000000231};
RX   PubMed=22675600; DOI=10.4056/sigs.2395367;
RA   Meincke L., Copeland A., Lapidus A., Lucas S., Berry K.W., Del Rio T.G.,
RA   Hammon N., Dalin E., Tice H., Pitluck S., Richardson P., Bruce D.,
RA   Goodwin L., Han C., Tapia R., Detter J.C., Schmutz J., Brettin T.,
RA   Larimer F., Land M., Hauser L., Kyrpides N.C., Ivanova N., Goker M.,
RA   Woyke T., Wu Q.L., Pockl M., Hahn M.W., Klenk H.P.;
RT   "Complete genome sequence of Polynucleobacter necessarius subsp.
RT   asymbioticus type strain (QLW-P1DMWA-1(T)).";
RL   Stand. Genomic Sci. 6:74-83(2012).
CC   -!- FUNCTION: Catalyzes the conversion of 2 pyruvate molecules into
CC       acetolactate in the first common step of the biosynthetic pathway of
CC       the branched-amino acids such as leucine, isoleucine, and valine.
CC       {ECO:0000256|RuleBase:RU368092}.
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         Evidence={ECO:0000256|ARBA:ARBA00000673,
CC         ECO:0000256|RuleBase:RU368092};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC       isoleucine from 2-oxobutanoate: step 1/4.
CC       {ECO:0000256|ARBA:ARBA00004974, ECO:0000256|RuleBase:RU368092}.
CC   -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC       pyruvate: step 1/4. {ECO:0000256|ARBA:ARBA00005025,
CC       ECO:0000256|RuleBase:RU368092}.
CC   -!- SUBUNIT: Dimer of large and small chains.
CC       {ECO:0000256|ARBA:ARBA00011744, ECO:0000256|RuleBase:RU368092}.
CC   -!- SIMILARITY: Belongs to the acetolactate synthase small subunit family.
CC       {ECO:0000256|ARBA:ARBA00006341, ECO:0000256|RuleBase:RU368092}.
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DR   EMBL; CP000655; ABP34278.1; -; Genomic_DNA.
DR   RefSeq; WP_011902903.1; NC_009379.1.
DR   AlphaFoldDB; A4SXR4; -.
DR   GeneID; 31481437; -.
DR   KEGG; pnu:Pnuc_1062; -.
DR   eggNOG; COG0440; Bacteria.
DR   HOGENOM; CLU_055003_1_3_4; -.
DR   UniPathway; UPA00047; UER00055.
DR   UniPathway; UPA00049; UER00059.
DR   Proteomes; UP000000231; Chromosome.
DR   GO; GO:0003984; F:acetolactate synthase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:1990610; F:acetolactate synthase regulator activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd04878; ACT_AHAS; 1.
DR   Gene3D; 3.30.70.260; -; 1.
DR   Gene3D; 3.30.70.1150; ACT-like. Chain A, domain 2; 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   NCBIfam; TIGR00119; acolac_sm; 1.
DR   PANTHER; PTHR30239; ACETOLACTATE SYNTHASE SMALL SUBUNIT; 1.
DR   PANTHER; PTHR30239:SF0; ACETOLACTATE SYNTHASE SMALL SUBUNIT 1, CHLOROPLASTIC; 1.
DR   Pfam; PF01842; ACT; 1.
DR   Pfam; PF10369; ALS_ss_C; 1.
DR   SUPFAM; SSF55021; ACT-like; 2.
DR   PROSITE; PS51671; ACT; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis {ECO:0000256|ARBA:ARBA00022605,
KW   ECO:0000256|RuleBase:RU368092};
KW   Branched-chain amino acid biosynthesis {ECO:0000256|ARBA:ARBA00023304,
KW   ECO:0000256|RuleBase:RU368092};
KW   Reference proteome {ECO:0000313|Proteomes:UP000000231};
KW   Transferase {ECO:0000256|RuleBase:RU368092, ECO:0000313|EMBL:ABP34278.1}.
FT   DOMAIN          4..78
FT                   /note="ACT"
FT                   /evidence="ECO:0000259|PROSITE:PS51671"
SQ   SEQUENCE   163 AA;  18081 MW;  4DB1121E69306061 CRC64;
     MRHIISVLIE NEPGALSRVV GLFSARGYNI DTLSVAPTED PSLSRMTIVT FGSDDVIEQI
     TKHLNRLVEV VKVFDLSEGP HIERELMMIK VRAVGKEREE LKRTTDIFRG RIIDVTDKSY
     TIELTGDGAK LDAFIDSIDR ASILETVRSG GSGIGRGERI LKV
//