ID   ILVH_NICPL              Reviewed;         449 AA.
AC   Q9SMC2;
DT   09-JAN-2013, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   25-MAY-2022, entry version 73.
DE   RecName: Full=Acetolactate synthase small subunit 1, chloroplastic;
DE   AltName: Full=Acetohydroxy-acid synthase small subunit;
DE            Short=AHAS;
DE            Short=ALS;
DE   Flags: Precursor;
OS   Nicotiana plumbaginifolia (Leadwort-leaved tobacco) (Tex-Mex tobacco).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Nicotianoideae; Nicotianeae;
OC   Nicotiana.
OX   NCBI_TaxID=4092;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND FUNCTION.
RX   PubMed=10487214; DOI=10.1023/a:1006273224977;
RA   Hershey H.P., Schwartz L.J., Gale J.P., Abell L.M.;
RT   "Cloning and functional expression of the small subunit of acetolactate
RT   synthase from Nicotiana plumbaginifolia.";
RL   Plant Mol. Biol. 40:795-806(1999).
CC   -!- FUNCTION: Regulatory subunit of acetohydroxy-acid synthase. Probably
CC       involved in feedback inhibition by branched-chain amino acids. Not
CC       involved in herbicide tolerance. {ECO:0000269|PubMed:10487214}.
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: The acetolactate synthase complex contains both large
CC       catalytic subunits and small regulatory subunits. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the acetolactate synthase small subunit family.
CC       {ECO:0000305}.
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DR   EMBL; AJ234901; CAB56614.1; -; mRNA.
DR   AlphaFoldDB; Q9SMC2; -.
DR   SMR; Q9SMC2; -.
DR   UniPathway; UPA00047; UER00055.
DR   UniPathway; UPA00049; UER00059.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
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; 2.
DR   Gene3D; 3.30.70.1150; -; 2.
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; 2.
DR   SUPFAM; SSF55021; SSF55021; 4.
DR   TIGRFAMs; TIGR00119; acolac_sm; 2.
DR   PROSITE; PS51671; ACT; 2.
PE   2: Evidence at transcript level;
KW   Amino-acid biosynthesis; Branched-chain amino acid biosynthesis;
KW   Chloroplast; Plastid; Repeat; Transit peptide.
FT   TRANSIT         1..30
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           31..449
FT                   /note="Acetolactate synthase small subunit 1,
FT                   chloroplastic"
FT                   /id="PRO_0000420832"
FT   DOMAIN          31..98
FT                   /note="ACT 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01007"
FT   DOMAIN          259..333
FT                   /note="ACT 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01007"
SQ   SEQUENCE   449 AA;  50113 MW;  D4CA826F37BCAD93 CRC64;
     MEHIQTRTTL SQLSTLPSDK RLGAIRFKCL LVMKVEMINR IAGVFARRGY NIESLAVGLN
     KDKALFTIVV SGTERVLQQV MEQLQKLVNV IKVEDLSKEP QVERELMLIK ISADPKYRAE
     VMWLVDVFRA KIVDISDQSL TIEVTGDPGK MVAVQRNLSK FGIREIARTG KIALRREKMG
     ESAPFWRFSA ASYPDLEGAM SAGTISRTIK RTPNGESMSM AEGDVYPVET DDNSGVSQVL
     DAHWGVLNDE DTSGLRSHTL SMLVNDTPGV LNIVTGVFAR RGYNIQSLAV GHAEVEGLSR
     ITTVVPGTDE SVSKLVQQLY KLVDIHEVRD ITHLPFAERE LMLIKIAVNA AARRNVLDIA
     SIFRAKAVDV SDHTITLELT GDLHKMVRLQ RLLEPYGICE VARTDVWHWY VNQVWIRSTC
     EDIHTLCSLK SSNLRKIPAL CGMCANVDD