ID   DCAM_NICSY              Reviewed;         361 AA.
AC   O80402;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1998, sequence version 1.
DT   25-MAY-2022, entry version 92.
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=SAMDC1; Synonyms=SAMDC-1;
OS   Nicotiana sylvestris (Wood tobacco) (South American 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=4096;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Nakakita M.;
RT   "Putative cDNA for S-adenosylmethionine decarboxylase from Nicotiana
RT   sylvestris.";
RL   Submitted (JUN-1998) to the EMBL/GenBank/DDBJ databases.
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; Evidence={ECO:0000250};
CC       Note=Binds 1 pyruvoyl group covalently per subunit. {ECO:0000250};
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; AB015609; BAA29040.1; -; mRNA.
DR   AlphaFoldDB; O80402; -.
DR   SMR; O80402; -.
DR   STRING; 4096.XP_009765510.1; -.
DR   eggNOG; KOG0788; Eukaryota.
DR   UniPathway; UPA00331; UER00451.
DR   Proteomes; UP000189701; Unplaced.
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; Reference proteome; S-adenosyl-L-methionine; Schiff base;
KW   Spermidine biosynthesis; Zymogen.
FT   CHAIN           1..72
FT                   /note="S-adenosylmethionine decarboxylase beta chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000030015"
FT   CHAIN           73..361
FT                   /note="S-adenosylmethionine decarboxylase alpha chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000030016"
FT   ACT_SITE        13
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        16
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        73
FT                   /note="Schiff-base intermediate with substrate; via pyruvic
FT                   acid"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        87
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            72..73
FT                   /note="Cleavage (non-hydrolytic); by autolysis"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         73
FT                   /note="Pyruvic acid (Ser); by autocatalysis"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   361 AA;  39681 MW;  648EB2F6CCC61FFE CRC64;
     MDMALPVSAI GFEGFEKRLE ISFFEPGLFA DPNGKGLRSL SKAQLDEILG PAECTIVDSL
     SNDDVDSYVL SESSLFVYSY KIIIKTCGTT KLLLAIPPIL KLAETLSLKV QDVRYTRGSF
     IFPGAQSFPH RHFSEEVAVL DGYFGKLAAG SKAVIMGSPD KAQKWHVYSA SAGPIQSNDP
     VYTLEMCMTG LDREKASVFY KTEGSSAAHM TVRSGIRKIL PNSEICDFEF EPCGYSMNSI
     EGAALSTIHI TPEDGFSYAS FEAVGYDMKT MKLGPLVERV LACFEPDEFS IALHADVATK
     LLERVCSVDV KGYSLAEWSP EEFGKGGSIV YQKFTRTPFC GSPKSVLKGC WKEDEEKEEK
     E