| Product Name |
homospermidine synthase (spermidine-specific) |
| Example Structure |
 |
| Synonyms |
homospermidine synthase, HSS, synthase, homospermidine, synthase, homospermidine (Senecio vernalis root gene HSS1) |
| EC Number |
2.5.1.45 |
| CAS Registry Number |
|
| Comments |
The reaction of this enzyme occurs in three steps: (i) NAD+-dependent dehydrogenation of spermidine, (ii) transfer of the 4-aminobutylidene group from dehydrospermidine to putrescine, (iii) reduction of the imine intermediate to form homospermidine. Hence the overall reaction is transfer of a 4-aminobutyl group. 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). |
| Cofactor |
NAD+ |
| History |
|
| Reactions |
Spermidine + putrescine = sym-homospermidine + propane-1,3-diamine. |
