ID   HSS1_SENVE              Reviewed;         370 AA.
AC   Q9SC13;
DT   21-NOV-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   03-AUG-2022, entry version 77.
DE   RecName: Full=Homospermidine synthase 1;
DE            EC=2.5.1.45;
GN   Name=HSS1;
OS   Senecio vernalis (Spring 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=93496;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN SEQUENCE OF 7-17; 151-159; 211-224
RP   AND 278-289.
RC   TISSUE=Root;
RX   PubMed=10611289; DOI=10.1073/pnas.96.26.14777;
RA   Ober D., Hartmann T.;
RT   "Homospermidine synthase, the first pathway-specific enzyme of
RT   pyrrolizidine alkaloid biosynthesis, evolved from deoxyhypusine synthase.";
RL   Proc. Natl. Acad. Sci. U.S.A. 96:14777-14782(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
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   -!- TISSUE SPECIFICITY: Expressed in roots.
CC   -!- PTM: The N-terminus is blocked.
CC   -!- SIMILARITY: Belongs to the deoxyhypusine synthase family.
CC       {ECO:0000305}.
CC   -!- CAUTION: Sequence shown in PubMed:10611289 correspond to the product of
CC       the second gene cited in PubMed:11117877. {ECO:0000305}.
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DR   EMBL; AJ238623; CAB65462.1; -; mRNA.
DR   AlphaFoldDB; Q9SC13; -.
DR   SMR; Q9SC13; -.
DR   KEGG; ag:CAB65462; -.
DR   BioCyc; MetaCyc:MON-13926; -.
DR   BRENDA; 2.5.1.45; 5675.
DR   SABIO-RK; Q9SC13; -.
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 1"
FT                   /id="PRO_0000134517"
SQ   SEQUENCE   370 AA;  40726 MW;  5E81E09C5A3A8689 CRC64;
     MAESNKEAID SARSNVFKES ESLEGTCAKI GGYDFNNGID HSKLLKSMVS TGFQASNLGD
     AMIITNQMLD 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