| Q4DA73 | n/a | 4yuy | 1SQ | A | 502 | e4yuyA1 | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermine_synt_N |
| Q4DA73 | n/a | 4yuy | 1SQ | A | 502 | e4yuyA2 | Rossmann-like | Rossmann-related | S-adenosyl-L-methionine-dependent methyltransferases | Spermine_synth |
| Q4DA73 | n/a | 4yuy | 1SQ | B | 502 | e4yuyB1 | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermidine synthase tetramerisation domain | Spermine_synt_N |
| Q4DA73 | n/a | 4yuy | 1SQ | B | 502 | e4yuyB2 | Rossmann-like | Rossmann-related | S-adenosyl-L-methionine-dependent methyltransferases | Spermine_synth |