ID   ILVB_CYACA              Reviewed;         585 AA.
AC   O19929;
DT   01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   03-AUG-2022, entry version 100.
DE   RecName: Full=Acetolactate synthase large subunit;
DE            Short=AHAS;
DE            EC=2.2.1.6;
DE   AltName: Full=Acetohydroxy-acid synthase large subunit;
DE            Short=ALS;
GN   Name=ilvB;
OS   Cyanidium caldarium (Red alga).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae; Cyanidium.
OX   NCBI_TaxID=2771;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=RK-1;
RX   PubMed=11040290; DOI=10.1007/s002390010101;
RA   Gloeckner G., Rosenthal A., Valentin K.-U.;
RT   "The structure and gene repertoire of an ancient red algal plastid
RT   genome.";
RL   J. Mol. Evol. 51:382-390(2000).
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   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250};
CC       Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000250};
CC   -!- COFACTOR:
CC       Name=thiamine diphosphate; Xref=ChEBI:CHEBI:58937;
CC         Evidence={ECO:0000250};
CC       Note=Binds 1 thiamine pyrophosphate per subunit. {ECO:0000250};
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   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
CC   -!- SIMILARITY: Belongs to the TPP enzyme family. {ECO:0000305}.
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DR   EMBL; AF022186; AAB82660.1; -; Genomic_DNA.
DR   PIR; T11997; T11997.
DR   RefSeq; NP_045101.1; NC_001840.1.
DR   AlphaFoldDB; O19929; -.
DR   SMR; O19929; -.
DR   GeneID; 800227; -.
DR   UniPathway; UPA00047; UER00055.
DR   UniPathway; UPA00049; UER00059.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0003984; F:acetolactate synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0050660; F:flavin adenine dinucleotide binding; IEA:InterPro.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:InterPro.
DR   GO; GO:0030976; F:thiamine pyrophosphate binding; 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; cd02015; TPP_AHAS; 1.
DR   InterPro; IPR012846; Acetolactate_synth_lsu.
DR   InterPro; IPR039368; AHAS_TPP.
DR   InterPro; IPR029035; DHS-like_NAD/FAD-binding_dom.
DR   InterPro; IPR029061; THDP-binding.
DR   InterPro; IPR012000; Thiamin_PyroP_enz_cen_dom.
DR   InterPro; IPR012001; Thiamin_PyroP_enz_TPP-bd_dom.
DR   InterPro; IPR000399; TPP-bd_CS.
DR   InterPro; IPR045229; TPP_enz.
DR   InterPro; IPR011766; TPP_enzyme-bd_C.
DR   PANTHER; PTHR18968; PTHR18968; 1.
DR   Pfam; PF02775; TPP_enzyme_C; 1.
DR   Pfam; PF00205; TPP_enzyme_M; 1.
DR   Pfam; PF02776; TPP_enzyme_N; 1.
DR   SUPFAM; SSF52467; SSF52467; 1.
DR   SUPFAM; SSF52518; SSF52518; 2.
DR   TIGRFAMs; TIGR00118; acolac_lg; 1.
DR   PROSITE; PS00187; TPP_ENZYMES; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Branched-chain amino acid biosynthesis;
KW   Chloroplast; FAD; Flavoprotein; Magnesium; Metal-binding; Plastid;
KW   Thiamine pyrophosphate; Transferase.
FT   CHAIN           1..585
FT                   /note="Acetolactate synthase large subunit"
FT                   /id="PRO_0000090809"
FT   REGION          407..486
FT                   /note="Thiamine pyrophosphate binding"
FT   BINDING         60
FT                   /ligand="thiamine diphosphate"
FT                   /ligand_id="ChEBI:CHEBI:58937"
FT                   /evidence="ECO:0000250"
FT   BINDING         162
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250"
FT   BINDING         272..293
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250"
FT   BINDING         315..334
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250"
FT   BINDING         457
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         484
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   585 AA;  65123 MW;  17D95558C6F76011 CRC64;
     MNYKKNSLIK TGAFALIDML VKHKVKNIFG YPGGAILPIY DELYHWEKKK LIKHYLVRHE
     QSAAHAADAY ARATNEVGVC LATSGPGATN LVTGIATAQM DSVPIIAITG QVSRAFIGTD
     AFQEVDIFGI TLPIVKHSFV VRDPRDISTI VSEAFYISKH GRPGAVLIDV PKDVGLEEFN
     YHDYDSIRDH KPITKYRPIY GPSIRQIEKF KKMLLESKQP ILYVGGGAVM SRAQHEIEEL
     ASFIKIPVTT TLMGKGSFNE YNPLYLGMLG MHGTAYANFA VSECDLLIAL GARFDDRVTG
     KLDEFACNAQ VIHVDIDPAE IGKNRIPQLA IISDIKIVLK ELLSSMKEGT NNMDKNQTQA
     WLHRIHKWKK EYPLSIPHDS KLLYPQEVIN EISQIAQKAF FATDVGQHQM WAAQFLKVEQ
     GKWLSSSGLG TMGYGLPAAI GAKIANPNDL IICITGDASF QMNLQELGTI AQYELDIKIF
     IINNQWQGMV RQWQQAFYDQ RYAHSNMAKG QPDFVQLANS YGIRGIRVTT SKDLKSKIER
     IISTPGPLLI DCIVATSENC YPMIAPGKSN SQMLGLTKQL KTITN