KEGG   ENZYME: 2.5.1.44Help
Entry
EC 2.5.1.44                 Enzyme                                 

Name
homospermidine synthase
Class
Transferases;
Transferring alkyl or aryl groups, other than methyl groups;
Transferring alkyl or aryl groups, other than methyl groups (only sub-subclass identified to date)
BRITE hierarchy
Sysname
putrescine:putrescine 4-aminobutyltransferase (ammonia-forming)
Reaction(IUBMB)
(1) 2 putrescine = sym-homospermidine + NH3 + H+ [RN:R00018];
(2) putrescine + spermidine = sym-homospermidine + propane-1,3-diamine [RN:R01919]
Reaction(KEGG)
Substrate
putrescine [CPD:C00134];
spermidine [CPD:C00315]
Product
sym-homospermidine [CPD:C06366];
NH3 [CPD:C00014];
H+ [CPD:C00080];
propane-1,3-diamine [CPD:C00986]
Comment
The reaction of this enzyme occurs in three steps, with some of the intermediates presumably remaining enzyme-bound: NAD+-dependent dehydrogenation of putrescine, transfer of the 4-aminobutylidene group from dehydroputrescine to a second molecule of putrescine and reduction of the imine intermediate to form homospermidine. Hence the overall reaction is transfer of a 4-aminobutyl group. Differs from EC 2.5.1.45, homospermidine synthase (spermidine-specific), which cannot use putrescine as donor of the aminobutyl group.
History
EC 2.5.1.44 created 1999, modified 2001
Pathway
Tropane, piperidine and pyridine alkaloid biosynthesis
Biosynthesis of secondary metabolites
Orthology
K00808  
homospermidine synthase
Genes
PAU: 
PAP: 
PDK: 
PAES: 
PAEU: 
PST: 
PSK: 
SAZ: 
AMAA: 
AMAL: 
AMAE: 
AMAO: 
AMAI: 
LPN: 
lpg2495(hss)
LPH: 
LPO: 
LPU: 
LPM: 
LPF: 
LPP: 
LPC: 
LPA: 
LPE: 
LLO: 
RPJ: 
REH: 
CTI: 
BGE: 
VAP: 
CBX: 
NEU: 
NE1498(hss)
NII: 
NMU: 
MLO: 
MCI: 
MOP: 
MAM: 
MES: 
PLA: 
SME: 
SMK: 
SMQ: 
SMX: 
SMI: 
SMEG: 
SMEL: 
SMER: 
SMD: 
RHI: 
SFH: 
SFD: 
EAD: 
ATU: 
ARA: 
AVI: 
AGR: 
RET: 
REC: 
REL: 
REI: 
RLE: 
RL4073(hss)
RLT: 
RLG: 
RLB: 
RLU: 
RTR: 
RIR: 
RHL: 
NGL: 
NGG: 
BME: 
BMZ: 
BMG: 
BMW: 
BMEE: 
BMF: 
BMB: 
BMC: 
BAA: 
BABO: 
BABR: 
BMS: 
BSI: 
BSF: 
BSUI: 
BMT: 
BSZ: 
BSV: 
BSW: 
BSG: 
BOV: 
BCS: 
BSK: 
BOL: 
BCAR: 
BCAS: 
BMR: 
BPP: 
BPV: 
BCET: 
BCEE: 
OAN: 
OAH: 
BJA: 
BJU: 
BRA: 
BBT: 
BRS: 
AOL: 
RPA: 
RPB: 
RPC: 
RPD: 
RPE: 
RPT: 
RPX: 
NWI: 
NHA: 
OCA: 
OCG: 
OCO: 
XAU: 
AZC: 
SNO: 
MEX: 
MEA: 
MDI: 
MCH: 
MRD: 
MET: 
MPO: 
MNO: 
MOR: 
BID: 
MSL: 
MSC: 
JAN: 
DSH: 
GBE: 
GBH: 
GBC: 
GBS: 
RCE: 
MAG: 
MGY: 
AZL: 
ALI: 
ABS: 
ABQ: 
TMO: 
MAI: 
MAN: 
PGV: 
OTE: 
TPX: 
CALO: 
PPH: 
MAC: 
MBA: 
MMA: 
MMAZ: 
MBN: 
MFO: 
 » show all
Taxonomy
Reference
1  [PMID:437275]
  Authors
Tait GH.
  Title
The formation of homospermidine by an enzyme from Rhodopseudomonas viridis [proceedings]
  Journal
Biochem. Soc. Trans. 7 (1979) 199-201.
Reference
2
  Authors
Bottcher, F., Ober, D. and Hartmann, T.
  Title
Biosynthesis of pyrrolizidine alkaloids: putrescine and spermidine are essential substrates of enzymatic homospermidine formation.
  Journal
Can. J. Chem. 72 (1994) 80-85.
Reference
3  [PMID:8407874]
  Authors
Yamamoto S, Nagata S, Kusaba K.
  Title
Purification and characterization of homospermidine synthase in Acinetobacter tartarogenes ATCC 31105.
  Journal
J. Biochem. (Tokyo). 114 (1993) 45-9.
Reference
4  [PMID:7470060]
  Authors
Srivenugopal KS, Adiga PR.
  Title
Enzymic synthesis of sym-homospermidine in Lathyrus sativus (grass pea) seedlings.
  Journal
Biochem. J. 190 (1980) 461-4.
Reference
5
  Authors
Ober, D., Tholl, D., Martin, W. and Hartmann, T.
  Title
Homospermidine synthase of Rhodopseudomonas viridis: Substrate specificity and effects of the heterologously expressed enzyme on polyamine metabolism of Escherichia coli.
  Journal
J. Gen. Appl. Microbiol. 42 (1996) 411-419.
Reference
6  [PMID:10611289]
  Authors
Ober D, Hartmann T.
  Title
Homospermidine synthase, the first pathway-specific enzyme of pyrrolizidine alkaloid biosynthesis, evolved from deoxyhypusine synthase.
  Journal
Proc. Natl. Acad. Sci. U. S. A. 96 (1999) 14777-82.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
76106-84-8

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