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EC 2.5.1.45 Details

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EC number

2.5.1.45

Accepted name

homospermidine synthase (spermidine-specific)

Reaction

spermidine + putrescine = sym-homospermidine + propane-1,3-diamine

Systematic name

spermidine:putrescine 4-aminobutyltransferase (propane-1,3-diamine-forming)

Comment

A eukaryotic enzyme found in plants. The reaction occurs in three steps, with some of the intermediates presumably remaining enzyme-bound: (a) NAD⁺-dependent dehydrogenation of spermidine to 4-iminobutan-1-amine, (b) attack by water forming 4-aminobutanal (and releasing propane-1,3-diamine), and (c) condensation of 4-aminobutanal with purescine, which forms homospermidine and restores NAD⁺. This enzyme is more specific than EC 2.5.1.44, homospermidine synthase, which is found in bacteria, as it cannot use putrescine as donor of the 4-aminobutyl group. Forms part of the biosynthetic pathway of the poisonous pyrrolizidine alkaloids of the ragworts (Senecio).

History

created 2001

EC Tree

1 Oxidoreductases

2.1 Transferring one-carbon groups

2.2 Transferring aldehyde or ketonic groups

2.3 Acyltransferases

2.4 Glycosyltransferases

2.5 Transferring alkyl or aryl groups, other than methyl groups

2.5.1 Transferring alkyl or aryl groups, other than methyl groups (only sub-subclass identified to date)

2.5.1.1 dimethylallyltranstransferase

2.5.1.2 thiamine pyridinylase

2.5.1.3 thiamine phosphate synthase

2.5.1.4 adenosylmethionine cyclotransferase

2.5.1.5 galactose-6-sulfurylase

2.5.1.6 methionine adenosyltransferase

2.5.1.7 UDP-N-acetylglucosamine 1-carboxyvinyltransferase

2.5.1.8 tRNA isopentenyltransferase

2.5.1.9 riboflavin synthase

2.5.1.10 (2E,6E)-farnesyl diphosphate synthase

2.5.1.11 trans-octaprenyltranstransferase

2.5.1.12 created 1972, deleted 1976

2.5.1.13 created 1972, deleted 1976

2.5.1.14 created 1972, deleted 1976

2.5.1.15 dihydropteroate synthase

2.5.1.16 spermidine synthase

2.5.1.17 corrinoid adenosyltransferase

2.5.1.18 glutathione transferase

2.5.1.19 3-phosphoshikimate 1-carboxyvinyltransferase

2.5.1.20 rubber cis-polyprenylcistransferase

2.5.1.21 squalene synthase

2.5.1.22 spermine synthase

2.5.1.23 sym-norspermidine synthase

2.5.1.24 discadenine synthase

2.5.1.25 tRNA-uridine aminocarboxypropyltransferase

2.5.1.26 alkylglycerone-phosphate synthase

2.5.1.27 adenylate dimethylallyltransferase (AMP-dependent)

2.5.1.28 dimethylallylcistransferase

2.5.1.29 geranylgeranyl diphosphate synthase

2.5.1.30 heptaprenyl diphosphate synthase

2.5.1.31 ditrans,polycis-undecaprenyl-diphosphate synthase [(2E,6E)-farnesyl-diphosphate specific]

2.5.1.32 15-cis-phytoene synthase

2.5.1.33 trans-pentaprenyltranstransferase

2.5.1.34 4-dimethylallyltryptophan synthase

2.5.1.35 aspulvinone dimethylallyltransferase

2.5.1.36 trihydroxypterocarpan dimethylallyltransferase

2.5.1.37 created 1989, deleted 2004

2.5.1.38 isonocardicin synthase

2.5.1.39 4-hydroxybenzoate polyprenyltransferase

2.5.1.40 created 1992, deleted 1999

2.5.1.41 phosphoglycerol geranylgeranyltransferase

2.5.1.42 geranylgeranylglycerol-phosphate geranylgeranyltransferase

2.5.1.43 nicotianamine synthase

2.5.1.44 homospermidine synthase

2.5.1.45 homospermidine synthase (spermidine-specific)

2.5.1.46 deoxyhypusine synthase

2.5.1.47 cysteine synthase

2.5.1.48 cystathionine γ-synthase

2.5.1.49 O-acetylhomoserine aminocarboxypropyltransferase

2.5.1.50 zeatin 9-aminocarboxyethyltransferase

2.5.1.51 β-pyrazolylalanine synthase

2.5.1.52 L-mimosine synthase

2.5.1.53 uracilylalanine synthase

2.5.1.54 3-deoxy-7-phosphoheptulonate synthase

2.5.1.55 3-deoxy-8-phosphooctulonate synthase

2.5.1.56 N-acetylneuraminate synthase

2.5.1.57 N-acylneuraminate-9-phosphate synthase

2.5.1.58 protein farnesyltransferase

2.5.1.59 protein geranylgeranyltransferase type I

2.5.1.60 protein geranylgeranyltransferase type II

2.5.1.61 hydroxymethylbilane synthase

2.5.1.62 chlorophyll synthase

2.5.1.63 adenosyl-fluoride synthase

2.5.1.64 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase

2.5.1.65 O-phosphoserine sulfhydrylase

2.5.1.66 N²-(2-carboxyethyl)arginine synthase

2.5.1.67 chrysanthemyl diphosphate synthase

2.5.1.68 (2Z,6E)-farnesyl diphosphate synthase

2.5.1.69 lavandulyl diphosphate synthase

2.5.1.70 naringenin 8-dimethylallyltransferase

2.5.1.71 leachianone-G 2′′-dimethylallyltransferase

2.5.1.72 quinolinate synthase

2.5.1.73 O-phospho-L-seryl-tRNA:Cys-tRNA synthase

2.5.1.74 1,4-dihydroxy-2-naphthoate polyprenyltransferase

2.5.1.75 tRNA dimethylallyltransferase

2.5.1.76 cysteate synthase

2.5.1.77 7,8-didemethyl-8-hydroxy-5-deazariboflavin synthase

2.5.1.78 6,7-dimethyl-8-ribityllumazine synthase

2.5.1.79 thermospermine synthase

2.5.1.80 7-dimethylallyltryptophan synthase

2.5.1.81 geranylfarnesyl diphosphate synthase

2.5.1.82 hexaprenyl diphosphate synthase [geranylgeranyl-diphosphate specific]

2.5.1.83 hexaprenyl diphosphate synthase [(2E,6E)-farnesyl-diphosphate specific]

2.5.1.84 all-trans-nonaprenyl diphosphate synthase [geranyl-diphosphate specific]

2.5.1.85 all-trans-nonaprenyl diphosphate synthase [geranylgeranyl-diphosphate specific]

2.5.1.86 trans,polycis-decaprenyl diphosphate synthase

2.5.1.87 ditrans,polycis-polyprenyl diphosphate synthase [(2E,6E)-farnesyl diphosphate specific]

2.5.1.88 trans,polycis-polyprenyl diphosphate synthase [(2Z,6E)-farnesyl diphosphate specific]

2.5.1.89 tritrans,polycis-undecaprenyl diphosphate synthase [geranylgeranyl-diphosphate specific]

2.5.1.90 all-trans-octaprenyl-diphosphate synthase

2.5.1.91 all-trans-decaprenyl-diphosphate synthase

2.5.1.92 (2Z,6Z)-farnesyl diphosphate synthase

2.5.1.93 4-hydroxybenzoate geranyltransferase

2.5.1.94 adenosyl-chloride synthase

2.5.1.95 xanthan ketal pyruvate transferase

2.5.1.96 4,4′-diapophytoene synthase

2.5.1.97 pseudaminic acid synthase

2.5.1.98 Rhizobium leguminosarum exopolysaccharide glucosyl ketal-pyruvate-transferase

2.5.1.99 all-trans-phytoene synthase

2.5.1.100 fumigaclavine A dimethylallyltransferase

2.5.1.101 N,N′-diacetyllegionaminate synthase

2.5.1.102 geranyl-pyrophosphate—olivetolic acid geranyltransferase

2.5.1.103 presqualene diphosphate synthase

2.5.1.104 N¹-aminopropylagmatine synthase

2.5.1.105 7,8-dihydropterin-6-yl-methyl-4-(β-D-ribofuranosyl)aminobenzene 5′-phosphate synthase

2.5.1.106 tryprostatin B synthase

2.5.1.107 verruculogen prenyltransferase

2.5.1.108 2-(3-amino-3-carboxypropyl)histidine synthase

2.5.1.109 brevianamide F prenyltransferase (deoxybrevianamide E-forming)

2.5.1.110 12α,13α-dihydroxyfumitremorgin C prenyltransferase

2.5.1.111 4-hydroxyphenylpyruvate 3-dimethylallyltransferase

2.5.1.112 adenylate dimethylallyltransferase (ADP/ATP-dependent)

2.5.1.113 [CysO sulfur-carrier protein]-thiocarboxylate-dependent cysteine synthase

2.5.1.114 tRNA^Phe (4-demethylwyosine³⁷-C7) aminocarboxypropyltransferase

2.5.1.115 homogentisate phytyltransferase

2.5.1.116 homogentisate geranylgeranyltransferase

2.5.1.117 homogentisate solanesyltransferase

2.5.1.118 β-(isoxazolin-5-on-2-yl)-L-alanine synthase

2.5.1.119 β-(isoxazolin-5-on-4-yl)-L-alanine synthase

2.5.1.120 aminodeoxyfutalosine synthase

2.5.1.121 5,10-dihydrophenazine-1-carboxylate 9-dimethylallyltransferase

2.5.1.122 4-O-dimethylallyl-L-tyrosine synthase

2.5.1.123 flaviolin linalyltransferase

2.5.1.124 6-linalyl-2-O,3-dimethylflaviolin synthase

2.5.1.125 7-geranyloxy-5-hydroxy-2-methoxy-3-methylnaphthalene-1,4-dione synthase

2.5.1.126 norspermine synthase

2.5.1.127 caldopentamine synthase

2.5.1.128 N⁴-bis(aminopropyl)spermidine synthase

2.5.1.129 flavin prenyltransferase

2.5.1.130 2-carboxy-1,4-naphthoquinone phytyltransferase

2.5.1.131 (4-{4-[2-(γ-L-glutamylamino)ethyl]phenoxymethyl}furan-2-yl)methanamine synthase

2.5.1.132 3-deoxy-D-glycero-D-galacto-nonulopyranosonate 9-phosphate synthase

2.5.1.133 bacteriochlorophyll a synthase

2.5.1.134 cystathionine β-synthase (O-acetyl-L-serine)

2.5.1.135 validamine 7-phosphate valienyltransferase

2.5.1.136 2-acylphloroglucinol 4-prenyltransferase

2.5.1.137 2-acyl-4-prenylphloroglucinol 6-prenyltransferase

2.5.1.138 coumarin 8-geranyltransferase

2.5.1.139 umbelliferone 6-dimethylallyltransferase

2.5.1.140 N-(2-amino-2-carboxyethyl)-L-glutamate synthase

2.5.1.141 heme o synthase

2.5.1.142 nerylneryl diphosphate synthase

2.5.1.143 pyridinium-3,5-biscarboxylic acid mononucleotide synthase

2.5.1.144 S-sulfo-L-cysteine synthase (O-acetyl-L-serine-dependent)

2.5.1.145 phosphatidylglycerol—prolipoprotein diacylglyceryl transferase

2.5.1.146 3-geranyl-3-[(Z)-2-isocyanoethenyl]indole synthase

2.5.1.147 5-amino-6-(D-ribitylamino)uracil—L-tyrosine 4-hydroxyphenyl transferase

2.5.1.148 lycopaoctaene synthase

2.5.1.149 lycopene elongase/hydratase (flavuxanthin-forming)

2.5.1.150 lycopene elongase/hydratase (dihydrobisanhydrobacterioruberin-forming)

2.5.1.151 alkylcobalamin dealkylase

2.5.1.152 D-histidine 2-aminobutanoyltransferase

2.5.1.153 adenosine tuberculosinyltransferase

2.5.1.154 corrinoid adenosyltransferase EutT

2.5.1.155 phosphoglycerol geranylfarnesyltransferase

2.5.1.156 geranylfarnesylglycerol-phosphate geranylfarnesyltransferase

2.6 Transferring nitrogenous groups

2.7 Transferring phosphorus-containing groups

2.8 Transferring sulfur-containing groups

2.9 Transferring selenium-containing groups

2.10 Transferring molybdenum- or tungsten-containing groups

5.1 Racemases and epimerases

5.2 cis-trans-Isomerases

5.3 Intramolecular oxidoreductases

5.4 Intramolecular transferases

5.5 Intramolecular lyases

5.6 Isomerases altering macromolecular conformation

5.99 Other isomerases

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Release 2023.1 (January 2023)