ID   HEM2_HORVU              Reviewed;         428 AA.
AC   Q42836;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 95.
DE   RecName: Full=Delta-aminolevulinic acid dehydratase, chloroplastic;
DE            Short=ALADH;
DE            EC=4.2.1.24;
DE   AltName: Full=Porphobilinogen synthase;
DE   Flags: Precursor;
GN   Name=HEMB; Synonyms=ALAD;
OS   Hordeum vulgare (Barley).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; BOP clade;
OC   Pooideae; Triticodae; Triticeae; Hordeinae; Hordeum.
OX   NCBI_TaxID=4513;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=cv. Bonus;
RA   Bougri O.;
RL   Submitted (OCT-1995) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Catalyzes an early step in the biosynthesis of tetrapyrroles.
CC       Binds two molecules of 5-aminolevulinate per subunit, each at a
CC       distinct site, and catalyzes their condensation to form porphobilinogen
CC       (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 5-aminolevulinate = H(+) + 2 H2O + porphobilinogen;
CC         Xref=Rhea:RHEA:24064, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:58126, ChEBI:CHEBI:356416; EC=4.2.1.24;
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250};
CC       Note=Binds 2 magnesium ions per monomer. The first magnesium ion is
CC       required for catalysis. The second functions as allosteric activator.
CC       {ECO:0000250};
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; protoporphyrin-IX
CC       biosynthesis; coproporphyrinogen-III from 5-aminolevulinate: step 1/4.
CC   -!- SUBUNIT: Homooctamer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
CC   -!- SIMILARITY: Belongs to the ALAD family. {ECO:0000305}.
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DR   EMBL; X92402; CAA63139.1; -; mRNA.
DR   PIR; T04472; T04472.
DR   AlphaFoldDB; Q42836; -.
DR   SMR; Q42836; -.
DR   PRIDE; Q42836; -.
DR   UniPathway; UPA00251; UER00318.
DR   ExpressionAtlas; Q42836; baseline and differential.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0004655; F:porphobilinogen synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0015995; P:chlorophyll biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0006782; P:protoporphyrinogen IX biosynthetic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 3.20.20.70; -; 1.
DR   InterPro; IPR001731; ALAD.
DR   InterPro; IPR030656; ALAD_AS.
DR   InterPro; IPR013785; Aldolase_TIM.
DR   PANTHER; PTHR11458; PTHR11458; 1.
DR   Pfam; PF00490; ALAD; 1.
DR   PRINTS; PR00144; DALDHYDRTASE.
DR   SMART; SM01004; ALAD; 1.
DR   PROSITE; PS00169; D_ALA_DEHYDRATASE; 1.
PE   2: Evidence at transcript level;
KW   Allosteric enzyme; Chlorophyll biosynthesis; Chloroplast;
KW   Heme biosynthesis; Lyase; Magnesium; Metal-binding; Plastid;
KW   Porphyrin biosynthesis; Transit peptide.
FT   TRANSIT         1..?
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           ?..428
FT                   /note="Delta-aminolevulinic acid dehydratase,
FT                   chloroplastic"
FT                   /id="PRO_0000013316"
FT   ACT_SITE        294
FT                   /note="Schiff-base intermediate with substrate"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        347
FT                   /note="Schiff-base intermediate with substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         304
FT                   /ligand="5-aminolevulinate"
FT                   /ligand_id="ChEBI:CHEBI:356416"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250"
FT   BINDING         316
FT                   /ligand="5-aminolevulinate"
FT                   /ligand_id="ChEBI:CHEBI:356416"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250"
FT   BINDING         332
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         373
FT                   /ligand="5-aminolevulinate"
FT                   /ligand_id="ChEBI:CHEBI:356416"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   BINDING         412
FT                   /ligand="5-aminolevulinate"
FT                   /ligand_id="ChEBI:CHEBI:356416"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   428 AA;  46213 MW;  2E3F6C37109816F7 CRC64;
     MASTVPFSPA KVQMFQATNC HGHAGFGSSF AVPRTGPRPR SVAVRVSSEQ EAAATVRAPS
     GRSIEECEAD AVAGRFPAPS CVCQTPKAPD GTPEIRPLDM AKRPRRNRRS PALRAAFQET
     SISPANLVLP LFIHEGEEDA PIGAMPGCFR LGWQHGLLAE VYKARDVGVN SFVLFPKVPD
     ALKSPTGVEA YNDNGLVPRT IRLLKDKFPD IIVYTDVALD PYSSDGHDGI VRKDGVILND
     ETVYQLCKQA VSQARAGADV VSPSNMMDGR VGAIRSALDA EGFNDVSIMS YTAKYASSFY
     GPFREALDSN PRFGDKKTYQ MNPANYREAL LETAADEAEG ADILLVKPGL PYLDIIRLSR
     DNSALPIAAY QVSGEYSMIK AGGALNMIDE EKVMMESLMC LRRAGADVIL TYFARQPPAV
     LCGMGTAK