CATH Classification
| Level | CATH Code | Description | 
|---|---|---|
 
	 | 
    2 | Mainly Beta | 
 
	 | 
    2.30 | Roll | 
 
	 | 
    2.30.140 | Spermidine Synthase; Chain: A, domain 2 | 
 
	 | 
    2.30.140.10 | Spermidine synthase, tetramerisation domain | 
Domain Context
CATH Clusters
| Superfamily | Spermidine synthase, tetramerisation domain | 
| Functional Family | Polyamine aminopropyltransferase | 
Enzyme Information
| 2.5.1.79 | 
							 Thermospermine synthase. 
							based on mapping to UniProt P09158 		
							S-adenosyl 3-(methylthio)propylamine + spermidine = S-methyl- 5'-thioadenosine + thermospermine + H(+). 
							-!- This enzyme is required for correct xylem specification through regulation of the lifetime of the xylem elements. 
						 | 
					
| 2.5.1.16 | 
							 Spermidine synthase. 
							based on mapping to UniProt P09158 		
							S-adenosyl 3-(methylthio)propylamine + putrescine = 5'-S-methyl- 5'-thioadenosine + spermidine. 
							-!- The enzymes from the plant Glycine max and from mammalia are highly specific for putrescine as the amine acceptor. -!- The enzymes from the bacteria Escherichia coli and Thermotoga maritima prefer putrescine but are more tolerant toward other amine acceptors, such as spermidine and cadaverine. -!- Cf. EC 2.5.1.22 and EC 2.5.1.23. 
						 | 
					
| 2.5.1.22 | 
							 Spermine synthase. 
							based on mapping to UniProt P09158 		
							S-adenosyl 3-(methylthio)propylamine + spermidine = S-methyl- 5'-thioadenosine + spermine. 
							-!- The enzyme from mammalia is highly specific for spermidine,  cf. EC 2.5.1.16 and EC 2.5.1.23. 
						 | 
					
| 2.5.1.- | 
							 Transferring alkyl or aryl groups, other than methyl groups. 
							based on mapping to UniProt P09158 		
							
							
						 | 
					
UniProtKB Entries (1)
| P09158 | 
						 SPEE_ECOLI 
						Escherichia coli K-12 
						Polyamine aminopropyltransferase 
					 | 
				
PDB Structure
| PDB | 3O4F | 
| External Links | |
| Method | X-RAY DIFFRACTION | 
| Organism | |
| Primary Citation | 
					 The crystal structure of Escherichia coli spermidine synthase SpeE reveals a unique substrate-binding pocket 
					    
					    J.Struct.Biol. 
					    
					 | 
			
