ID   DCAM_HORCH              Reviewed;         393 AA.
AC   Q42829;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=S-adenosylmethionine decarboxylase proenzyme;
DE            Short=AdoMetDC;
DE            Short=SAMDC;
DE            EC=4.1.1.50;
DE   Contains:
DE     RecName: Full=S-adenosylmethionine decarboxylase alpha chain;
DE   Contains:
DE     RecName: Full=S-adenosylmethionine decarboxylase beta chain;
DE   Flags: Precursor;
GN   Name=SAMDC;
OS   Hordeum chilense (Barley) (Critesion chilense).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; BOP clade;
OC   Pooideae; Triticodae; Triticeae; Hordeinae; Hordeum.
OX   NCBI_TaxID=15565;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Leaf;
RX   PubMed=8639739; DOI=10.1007/bf00020812;
RA   Dresselhaus T., Barcelo P., Hagel C., Loerz H., Humbeck K.;
RT   "Isolation and characterization of a Tritordeum cDNA encoding S-
RT   adenosylmethionine decarboxylase that is circadian-clock-regulated.";
RL   Plant Mol. Biol. 30:1021-1033(1996).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H(+) + S-adenosyl-L-methionine = CO2 + S-adenosyl 3-
CC         (methylsulfanyl)propylamine; Xref=Rhea:RHEA:15981, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:16526, ChEBI:CHEBI:57443, ChEBI:CHEBI:59789; EC=4.1.1.50;
CC   -!- COFACTOR:
CC       Name=pyruvate; Xref=ChEBI:CHEBI:15361;
CC       Note=Binds 1 pyruvoyl group covalently per subunit.;
CC   -!- PATHWAY: Amine and polyamine biosynthesis; S-adenosylmethioninamine
CC       biosynthesis; S-adenosylmethioninamine from S-adenosyl-L-methionine:
CC       step 1/1.
CC   -!- PTM: Is synthesized initially as an inactive proenzyme. Formation of
CC       the active enzyme involves a self-maturation process in which the
CC       active site pyruvoyl group is generated from an internal serine residue
CC       via an autocatalytic post-translational modification. Two non-identical
CC       subunits are generated from the proenzyme in this reaction, and the
CC       pyruvate is formed at the N-terminus of the alpha chain, which is
CC       derived from the carboxyl end of the proenzyme. The post-translation
CC       cleavage follows an unusual pathway, termed non-hydrolytic serinolysis,
CC       in which the side chain hydroxyl group of the serine supplies its
CC       oxygen atom to form the C-terminus of the beta chain, while the
CC       remainder of the serine residue undergoes an oxidative deamination to
CC       produce ammonia and the pyruvoyl group blocking the N-terminus of the
CC       alpha chain (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the eukaryotic AdoMetDC family. {ECO:0000305}.
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DR   EMBL; X83881; CAA58762.1; -; mRNA.
DR   PIR; S69191; S69191.
DR   AlphaFoldDB; Q42829; -.
DR   SMR; Q42829; -.
DR   UniPathway; UPA00331; UER00451.
DR   GO; GO:0004014; F:adenosylmethionine decarboxylase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006557; P:S-adenosylmethioninamine biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0008295; P:spermidine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0006597; P:spermine biosynthetic process; IEA:InterPro.
DR   InterPro; IPR001985; S-AdoMet_decarboxylase.
DR   InterPro; IPR016067; S-AdoMet_deCO2ase_core.
DR   InterPro; IPR018166; S-AdoMet_deCO2ase_CS.
DR   PANTHER; PTHR11570; PTHR11570; 1.
DR   Pfam; PF01536; SAM_decarbox; 1.
DR   PIRSF; PIRSF001355; S-AdenosylMet_decarboxylase; 1.
DR   SUPFAM; SSF56276; SSF56276; 1.
DR   TIGRFAMs; TIGR00535; SAM_DCase; 1.
DR   PROSITE; PS01336; ADOMETDC; 1.
PE   2: Evidence at transcript level;
KW   Autocatalytic cleavage; Decarboxylase; Lyase; Polyamine biosynthesis;
KW   Pyruvate; S-adenosyl-L-methionine; Schiff base; Spermidine biosynthesis;
KW   Zymogen.
FT   CHAIN           1..70
FT                   /note="S-adenosylmethionine decarboxylase beta chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000030009"
FT   CHAIN           71..393
FT                   /note="S-adenosylmethionine decarboxylase alpha chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000030010"
FT   ACT_SITE        11
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        14
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        71
FT                   /note="Schiff-base intermediate with substrate; via pyruvic
FT                   acid"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        85
FT                   /note="Proton donor; for catalytic activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        236
FT                   /note="Proton acceptor; for processing activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        249
FT                   /note="Proton acceptor; for processing activity"
FT                   /evidence="ECO:0000250"
FT   SITE            70..71
FT                   /note="Cleavage (non-hydrolytic); by autolysis"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         71
FT                   /note="Pyruvic acid (Ser); by autocatalysis"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   393 AA;  42896 MW;  6CD1AA94792AF6CB CRC64;
     MAAPVSAIGF EGYEKRLEIT FSEASIFADP HGRGLRALSR AQIDSVLDLA RCTIVSELSN
     KDFDSYVLSE SSLFIYSQKI VIKTCGTTML LLTIPRILEL AEELCMPLAA VKYSRGMFIF
     PGAQPAPHRS FSEEVDVLNR YFGHLNSGGN AYVIGDPAKP GQKWHIYYAT EQPEQPMVTL
     EMCMTGLDKT KASVFFKTHA DGHVSCAKEM TKLSGISDII PEMEVCDFDF EPCGYSMNAI
     NGSAFSTIHV TPEDGFSYAS YEVQGMDASA LAYGDIVKRV LRCFGPSEFS VAVTIFGGRG
     HAATWGKKLD AEAYDCNNVV EQELPCGGVL IYQSFAANEE LAVSAGSPRS VFHCFENVES
     GHPLVKEGKL ANLLAWRAEE ESLEEGTGAL LCE