| Q8II73 | n/a | 4bp3 | 4MN | A | 401 | e4bp3A1 | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermine_synt_N |
| Q8II73 | n/a | 4bp3 | 4MN | A | 401 | e4bp3A2 | Rossmann-like | Rossmann-related | S-adenosyl-L-methionine-dependent methyltransferases | Spermine_synth |
| Q8II73 | n/a | 4bp3 | 4MN | B | 401 | e4bp3B1 | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermine_synt_N |
| Q8II73 | n/a | 4bp3 | 4MN | B | 401 | e4bp3B2 | Rossmann-like | Rossmann-related | S-adenosyl-L-methionine-dependent methyltransferases | Spermine_synth |
| Q8II73 | n/a | 4bp3 | 4MN | C | 401 | e4bp3C1 | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermine_synt_N |
| Q8II73 | n/a | 4bp3 | 4MN | C | 401 | e4bp3C2 | Rossmann-like | Rossmann-related | S-adenosyl-L-methionine-dependent methyltransferases | Spermine_synth |