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 02-SEP-2026, entry version 85. 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 = sym-homospermidine + propane-1,3- CC diamine; Xref=Rhea:RHEA:11236, ChEBI:CHEBI:57484, ChEBI:CHEBI:57811, CC ChEBI:CHEBI:57834, ChEBI:CHEBI:326268; 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}. 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; AJ238623; CAB65462.1; -; mRNA. DR AlphaFoldDB; Q9SC13; -. DR SMR; Q9SC13; -. DR KEGG; ag:CAB65462; -. DR BioCyc; MetaCyc:MONOMER-13926; -. DR BRENDA; 2.5.1.45; 5675. DR SABIO-RK; Q9SC13; -. DR UniPathway; UPA00329; -. DR GO; GO:0005737; C:cytoplasm; IEA:TreeGrafter. DR GO; GO:0034038; F:deoxyhypusine synthase activity; IEA:TreeGrafter. DR GO; GO:0050514; F:homospermidine synthase (spermidine-specific) activity; IEA:UniProtKB-EC. DR GO; GO:0008612; P:peptidyl-hypusine biosynthetic process; IEA:InterPro. DR FunFam; 3.40.910.10:FF:000002; Deoxyhypusine synthase; 1. DR Gene3D; 3.40.910.10; Deoxyhypusine synthase; 1. DR InterPro; IPR002773; Deoxyhypusine_synthase. DR InterPro; IPR036982; Deoxyhypusine_synthase_sf. DR InterPro; IPR029035; DHS-like_NAD/FAD-binding_dom. DR NCBIfam; TIGR00321; dhys; 1. DR PANTHER; PTHR11703; DEOXYHYPUSINE SYNTHASE; 1. DR PANTHER; PTHR11703:SF0; DEOXYHYPUSINE SYNTHASE; 1. DR Pfam; PF01916; DS; 1. DR SUPFAM; SSF52467; DHS-like NAD/FAD-binding domain; 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 //