ID   SPDS2_HYONI             Reviewed;         308 AA.
AC   O48659;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-1998, sequence version 1.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Spermidine synthase 2;
DE            Short=SPDSY 2;
DE            EC=2.5.1.16;
DE   AltName: Full=Putrescine aminopropyltransferase 2;
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}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AB006691; BAA24534.1; -; mRNA.
DR   AlphaFoldDB; O48659; -.
DR   SMR; O48659; -.
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 2"
FT                   /id="PRO_0000156454"
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;  33917 MW;  18E42E9DA82283EB CRC64;
     MEEQGNNESA YISSILPGWF SEISPLWPGE AHSLKVEKIL FQGKSDYQNV VVFQSSTYGK
     VLVLDGVIQL TERDECAYQE MITHLPLCSI PNPKKVLVIG GGDGGVLREV SRHSSVEQID
     ICEIDKMVID VSKQFFPNVA IGYEDPRVKL HVGDGVAFLK NVPEGTYDAV IVDSSDPIGP
     AQELFEKPFF ESVARALCPG GVVCTQAESI WLHMHIIEDI VSNCRQIFKG SVNYAWTTVP
     TYPSGVIGFM LCSTEGPAVD FKNPINPIDA DDSHTKTRGP LKFYNSEIHS ASFCLPSFAK
     RVIESNAK