ID   SPDS1_HYONI             Reviewed;         315 AA.
AC   O48658;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-1998, sequence version 1.
DT   03-AUG-2022, entry version 88.
DE   RecName: Full=Spermidine synthase 1;
DE            Short=SPDSY 1;
DE            EC=2.5.1.16;
DE   AltName: Full=Putrescine aminopropyltransferase 1;
OS   Hyoscyamus niger (Black henbane).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Solanales; Solanaceae; Solanoideae; Hyoscyameae;
OC   Hyoscyamus.
OX   NCBI_TaxID=4079;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Root;
RX   PubMed=9517003; DOI=10.1093/oxfordjournals.pcp.a029291;
RA   Hashimoto T., Tamaki K., Suzuki K., Yamada Y.;
RT   "Molecular cloning of plant spermidine synthases.";
RL   Plant Cell Physiol. 39:73-79(1998).
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; AB006690; BAA24533.1; -; mRNA.
DR   AlphaFoldDB; O48658; -.
DR   SMR; O48658; -.
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..315
FT                   /note="Spermidine synthase 1"
FT                   /id="PRO_0000156453"
FT   DOMAIN          25..262
FT                   /note="PABS"
FT   ACT_SITE        181
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250"
FT   BINDING         56
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         86
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
FT   BINDING         87
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         111
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         131
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         162..163
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         181..184
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
FT   BINDING         181
FT                   /ligand="S-adenosyl 3-(methylsulfanyl)propylamine"
FT                   /ligand_id="ChEBI:CHEBI:57443"
FT                   /evidence="ECO:0000250"
FT   BINDING         250
FT                   /ligand="putrescine"
FT                   /ligand_id="ChEBI:CHEBI:326268"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   315 AA;  34661 MW;  384192D51CE7BABF CRC64;
     MEVTNQSNGC SNNEKESPYI SSVLPGWFSE ISPLWPGEAH SLKVEKILFQ GKSDYQNVMV
     FQSSTYGKVL VLDGVIQLTE RDECAYQEMI THLPLCSIPN PKKVLVIGGG DGGVLREVSR
     HSSVEQIDIC EIDKMVVEVA KEFFPDVAVG YEDPRVNLHI GDGVAFLKNV PAGTYDAVIV
     DSSDPIGPAQ ELFEKPFFES IARALRPGGV VSTQAESIWL HMHIIEEIVA NCRQIFKGSV
     NYAWTTVPTY PSGMIGFMLC STEGPAVDFK NPINPIDDES GPKTIAPLKF YNSEIHQASF
     CLPSFAKRVI ESKGK