ID   HSS1_SENVU              Reviewed;         370 AA.
AC   Q9M4B0; Q9ST60;
DT   21-NOV-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   03-AUG-2022, entry version 73.
DE   RecName: Full=Homospermidine synthase;
DE            EC=2.5.1.45;
GN   Name=HSS1;
OS   Senecio vulgaris (Common groundsel).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; campanulids; Asterales; Asteraceae; Asteroideae; Senecioneae;
OC   Senecioninae; Senecio.
OX   NCBI_TaxID=76276;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN SEQUENCE OF 7-17; 149-159; 211-224
RP   AND 278-289.
RX   PubMed=10476066; DOI=10.1046/j.1365-313x.1999.00509.x;
RA   Kaiser A.E.;
RT   "Cloning and expression of a cDNA encoding homospermidine synthase from
RT   Senecio vulgaris (Asteraceae) in Escherichia coli.";
RL   Plant J. 19:195-201(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND SEQUENCE REVISION.
RC   TISSUE=Root;
RX   PubMed=11117877; DOI=10.1016/s0031-9422(00)00267-3;
RA   Ober D., Harms R., Hartmann T.;
RT   "Cloning and expression of homospermidine synthase from Senecio vulgaris: a
RT   revision.";
RL   Phytochemistry 55:305-309(2000).
CC   -!- FUNCTION: Catalyzes the transfer of an aminobutyl unit from spermidine
CC       onto putrescine. The resulting polyamine homospermidine is a precursor
CC       in the biosynthesis of pyrrolizidine alkaloids.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=putrescine + spermidine = propane-1,3-diamine + sym-
CC         homospermidine; Xref=Rhea:RHEA:11236, ChEBI:CHEBI:57484,
CC         ChEBI:CHEBI:57811, ChEBI:CHEBI:57834, ChEBI:CHEBI:326268;
CC         EC=2.5.1.45;
CC   -!- COFACTOR:
CC       Name=NAD(+); Xref=ChEBI:CHEBI:57540;
CC   -!- PATHWAY: Alkaloid biosynthesis; pyrrolizidine alkaloid biosynthesis.
CC   -!- SUBUNIT: Homotetramer.
CC   -!- SIMILARITY: Belongs to the deoxyhypusine synthase family.
CC       {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=CAB52544.1; Type=Frameshift; Evidence={ECO:0000305};
CC       Sequence=CAB52544.1; Type=Miscellaneous discrepancy; Note=Sequencing errors.; Evidence={ECO:0000305};
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DR   EMBL; AJ010120; CAB52544.1; ALT_SEQ; mRNA.
DR   EMBL; AJ251500; CAB66389.1; -; mRNA.
DR   AlphaFoldDB; Q9M4B0; -.
DR   SMR; Q9M4B0; -.
DR   BioCyc; MetaCyc:MON-13925; -.
DR   BRENDA; 2.5.1.45; 5676.
DR   UniPathway; UPA00329; -.
DR   GO; GO:0050514; F:homospermidine synthase (spermidine-specific) activity; IEA:UniProtKB-EC.
DR   GO; GO:0008612; P:peptidyl-lysine modification to peptidyl-hypusine; IEA:InterPro.
DR   Gene3D; 3.40.910.10; -; 1.
DR   InterPro; IPR002773; Deoxyhypusine_synthase.
DR   InterPro; IPR036982; Deoxyhypusine_synthase_sf.
DR   InterPro; IPR029035; DHS-like_NAD/FAD-binding_dom.
DR   PANTHER; PTHR11703; PTHR11703; 1.
DR   Pfam; PF01916; DS; 1.
DR   SUPFAM; SSF52467; SSF52467; 1.
DR   TIGRFAMs; TIGR00321; dhys; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; NAD; Transferase.
FT   CHAIN           1..370
FT                   /note="Homospermidine synthase"
FT                   /id="PRO_0000134519"
SQ   SEQUENCE   370 AA;  40740 MW;  5FF63BF12B6AC39D CRC64;
     MAESNKEAID SARSNVFKES ESLEGTCAKI GGYDFNNGID HSKLLKSMVS TGFQASNLGD
     AMIITNQMLE WRLSHDEVPE NCSEEEKKNR ESVKCKIFLG FTSNLISSGV RETICYLTQH
     RMVDVLVTTT GGIEEDFIKC LASTYKGKFS LPGADLRSKG LNRIGNLIVP NDNYIKFEDW
     IIPIFDQMLI EQKTQNVLWT PSRMIARLGK EINNETSYLY WAYKNNIPVF CPSITDGSIG
     DMLYFHSVSN PGPGLVVDIV QDVIAMDNEA VHASPQKTGI IILGGGLPKH HICNANMMRN
     GADFAVFINT AQEYDGSDSG ARPDEAVSWG KISSTGKAVK VHCDATIAFP LLVAETFAVK
     KEKASKVNGF