ID Q85G80_CYAM1 Unreviewed; 174 AA.
AC Q85G80;
DT 01-JUN-2003, integrated into UniProtKB/TrEMBL.
DT 01-JUN-2003, sequence version 1.
DT 27-MAR-2024, entry version 90.
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 Name=ilvH {ECO:0000313|EMBL:BAC76110.1};
OS Cyanidioschyzon merolae (strain NIES-3377 / 10D) (Unicellular red alga).
OG Plastid; Chloroplast {ECO:0000313|EMBL:BAC76110.1}.
OC Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae;
OC Cyanidioschyzon.
OX NCBI_TaxID=280699 {ECO:0000313|EMBL:BAC76110.1, ECO:0000313|Proteomes:UP000007014};
RN [1] {ECO:0000313|EMBL:BAC76110.1, ECO:0000313|Proteomes:UP000007014}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=10D {ECO:0000313|EMBL:BAC76110.1,
RC ECO:0000313|Proteomes:UP000007014};
RX PubMed=12755171; DOI=10.1093/dnares/10.2.67;
RA Ohta N., Matsuzaki M., Misumi O., Miyagishima S., Nozaki H., Tanaka K.,
RA Shin-i T., Kohara Y., Kuroiwa T.;
RT "Complete sequence and analysis of the plastid genome of the unicellular
RT red alga Cyanidioschyzon merolae.";
RL DNA Res. 10:67-77(2003).
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|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|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; AB002583; BAC76110.1; -; Genomic_DNA.
DR RefSeq; NP_848948.1; NC_004799.1.
DR AlphaFoldDB; Q85G80; -.
DR STRING; 280699.Q85G80; -.
DR EnsemblPlants; CMV018CT; CMV018CT; CMV018C.
DR GeneID; 844895; -.
DR Gramene; CMV018CT; CMV018CT; CMV018C.
DR KEGG; cme:CymeCp016; -.
DR eggNOG; KOG2663; Eukaryota.
DR HOGENOM; CLU_055003_3_0_1; -.
DR OMA; RPFGIKE; -.
DR UniPathway; UPA00047; UER00055.
DR UniPathway; UPA00049; UER00059.
DR Proteomes; UP000007014; Chloroplast.
DR GO; GO:0009507; C:chloroplast; IEA:UniProtKB-KW.
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; PF13710; ACT_5; 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}; Chloroplast {ECO:0000313|EMBL:BAC76110.1};
KW Plastid {ECO:0000313|EMBL:BAC76110.1};
KW Reference proteome {ECO:0000313|Proteomes:UP000007014};
KW Transferase {ECO:0000256|RuleBase:RU368092}.
FT DOMAIN 4..78
FT /note="ACT"
FT /evidence="ECO:0000259|PROSITE:PS51671"
SQ SEQUENCE 174 AA; 19356 MW; 06AFC740587D94B7 CRC64;
MKHTLSVLVE DEAGVLTRIA GLFARRSFNI ESLAVGPAEQ AGISRITMVV PGDDRTIEQL
MKQLYKLIPI LQVENLTQVP CVERELILMK VQANSQTRRE ILDMANIFRA RVVDISADDV
MLEVTGDPGK MVALEQILTK FGIVEVARTG KIALKRSSKV NTEWLRYNFG EGGT
//
