ID   SPDS1_DATST             Reviewed;         308 AA.
AC   Q96556;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   03-AUG-2022, entry version 89.
DE   RecName: Full=Spermidine synthase 1;
DE            Short=SPDSY 1;
DE            EC=2.5.1.16;
DE   AltName: Full=Putrescine aminopropyltransferase 1;
OS   Datura stramonium (Jimsonweed) (Common thornapple).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Solanoideae; Datureae; Datura.
OX   NCBI_TaxID=4076;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=D5/15; TISSUE=Root;
RA   Michael A.J.;
RL   Submitted (SEP-1996) to the EMBL/GenBank/DDBJ databases.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=putrescine + S-adenosyl 3-(methylsulfanyl)propylamine = H(+) +
CC         S-methyl-5'-thioadenosine + spermidine; Xref=Rhea:RHEA:12721,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:17509, ChEBI:CHEBI:57443,
CC         ChEBI:CHEBI:57834, ChEBI:CHEBI:326268; EC=2.5.1.16;
CC   -!- PATHWAY: Amine and polyamine biosynthesis; spermidine biosynthesis;
CC       spermidine from putrescine: step 1/1.
CC   -!- SIMILARITY: Belongs to the spermidine/spermine synthase family.
CC       {ECO:0000305}.
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DR   EMBL; Y08252; CAA69420.1; -; mRNA.
DR   AlphaFoldDB; Q96556; -.
DR   SMR; Q96556; -.
DR   UniPathway; UPA00248; UER00314.
DR   GO; GO:0004766; F:spermidine synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0008295; P:spermidine biosynthetic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 2.30.140.10; -; 1.
DR   Gene3D; 3.40.50.150; -; 1.
DR   HAMAP; MF_00198; Spermidine_synth; 1.
DR   InterPro; IPR030374; PABS.
DR   InterPro; IPR030373; PABS_CS.
DR   InterPro; IPR029063; SAM-dependent_MTases_sf.
DR   InterPro; IPR001045; Spermi_synthase.
DR   InterPro; IPR030668; Spermi_synthase_euk.
DR   InterPro; IPR035246; Spermidine_synt_N.
DR   InterPro; IPR037163; Spermidine_synt_N_sf.
DR   PANTHER; PTHR11558; PTHR11558; 1.
DR   Pfam; PF17284; Spermine_synt_N; 1.
DR   PIRSF; PIRSF000502; Spermidine_synth; 1.
DR   SUPFAM; SSF53335; SSF53335; 1.
DR   TIGRFAMs; TIGR00417; speE; 1.
DR   PROSITE; PS01330; PABS_1; 1.
DR   PROSITE; PS51006; PABS_2; 1.
PE   2: Evidence at transcript level;
KW   Polyamine biosynthesis; Spermidine biosynthesis; Transferase.
FT   CHAIN           1..308
FT                   /note="Spermidine synthase 1"
FT                   /id="PRO_0000156451"
FT   DOMAIN          17..254
FT                   /note="PABS"
FT   ACT_SITE        173
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250"
FT   BINDING         48
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         78
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
FT   BINDING         79
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         103
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         123
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         154..155
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         173..176
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
FT   BINDING         173
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         242
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   308 AA;  34033 MW;  820631DC791EF0DB CRC64;
     MEEANNKESP YISSILPGWF SEISPLWPGE AHSLKVEKIL FQGKSDYQNV MVFQSSTYGK
     VLILDGVIQL TERDECAYQE MITHLPLCSI PNPKKVLVIG GGDGGVLREV SRHSSVEQID
     ICEIDKMVID VSKQFFPNVA IGYEDPRVKL HVGDGVAFLK FVAEGTYDAV IVDSSDPIGP
     AQELFEKPFF ESVARALRPG GVVCTQAESI WLHMHIIEDI VANCRQIFKG SVNYAWTTVP
     TYPSGVIGFM LCSTEGPAVD FKNPINPVDA DDSHTKTRGP LKFYNSEIHS ASFCLPSFAK
     RVIESKGK