ID   DCAM3_BRAJU             Reviewed;         367 AA.
AC   Q9SDM8;
DT   14-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   25-MAY-2022, entry version 86.
DE   RecName: Full=S-adenosylmethionine decarboxylase proenzyme 3;
DE            Short=AdoMetDC 3;
DE            Short=SAMDC 3;
DE            EC=4.1.1.50;
DE   Contains:
DE     RecName: Full=S-adenosylmethionine decarboxylase 3 alpha chain;
DE   Contains:
DE     RecName: Full=S-adenosylmethionine decarboxylase 3 beta chain;
DE   Flags: Precursor;
GN   Name=SAMDC3;
OS   Brassica juncea (Indian mustard) (Sinapis juncea).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; malvids; Brassicales; Brassicaceae; Brassiceae; Brassica.
OX   NCBI_TaxID=3707;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Hu W.W., Pua E.-C.;
RL   Submitted (DEC-1999) 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; AF215665; AAF20160.1; -; mRNA.
DR   AlphaFoldDB; Q9SDM8; -.
DR   SMR; Q9SDM8; -.
DR   BRENDA; 4.1.1.50; 941.
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..68
FT                   /note="S-adenosylmethionine decarboxylase 3 beta chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000029995"
FT   CHAIN           69..367
FT                   /note="S-adenosylmethionine decarboxylase 3 alpha chain"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000029996"
FT   ACT_SITE        9
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        12
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        69
FT                   /note="Schiff-base intermediate with substrate; via pyruvic
FT                   acid"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        83
FT                   /note="Proton donor; for catalytic activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        234
FT                   /note="Proton acceptor; for processing activity"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        247
FT                   /note="Proton acceptor; for processing activity"
FT                   /evidence="ECO:0000250"
FT   SITE            68..69
FT                   /note="Cleavage (non-hydrolytic); by autolysis"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         69
FT                   /note="Pyruvic acid (Ser); by autocatalysis"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   367 AA;  40489 MW;  3333B68A74FA398F CRC64;
     MALSAIGFEG YEKRLEVSFF EPSFFQDSKG LGLRALTRSQ LDEILTPAAC EIVSSLSNDH
     LDSYVLSESS FFVYPYKVII KTCGTTKLLL SIPPLLKLAG ELSLSVKSVK YTRGSFLCPG
     GQPFPHRSFS EEVSVLDGHF TKLGLNSVAY LMGNDDENKK WHVYAASAQT SSDCNNNVYT
     LEMCMTGLDK EKASVFYKNE TGGENGSMTD NSGIRKILPK SQICDFEFEP CGYSMNSVEG
     DAISTIHVTP EDGFSYASFE AVGYDFNTLD LSQLVTRVLS CFEPKQFSVA VHSSVGSNAY
     KPEISVDLED YGCRERTFES LGEESGTVMY QTFEKLGKYC GSPRSTLKCE WSSNNSCSSE
     DEKDEGI