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CATH Superfamily 2.30.140.10

Spermidine synthase, tetramerisation domain

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

"
Spermidine synthase, tetramerisation domain
".

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 23: Polyamine aminopropyltransferase 1

There are 4 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Spermidine synthase. [EC: 2.5.1.16]
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.
 1 O66473
Caldopentamine synthase. [EC: 2.5.1.127]
S-adenosyl 3-(methylthio)propylamine + norspermine = S-methyl- 5'-thioadenosine + caldopentamine.
  • The enzyme, characterized from the thermophilic archaeon Hyperthermus butylicus, can also synthesize norspermine from norspermidine and thermospermine from spermidine (with lower activity).
  • The long-chain polyamines stabilize double-stranded DNA at high temperatures.
  • In contrast to EC 2.5.1.23 and EC 2.5.1.126, this enzyme shows no activity with propane-1,3-diamine.
 1 A2BIX4
Thermospermine synthase. [EC: 2.5.1.79]
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.
 1 A2BIX4
Norspermine synthase. [EC: 2.5.1.126]
S-adenosyl 3-(methylthio)propylamine + norspermidine = S-methyl- 5'-thioadenosine + norspermine.
  • The enzyme, characterized from the thermophilic archaeon Pyrobaculum aerophilum, can also synthesize norspermidine from propane-1,3- diamine and thermospermine from spermidine (with lower activity).
  • The long-chain polyamines stabilize double-stranded DNA at high temperatures.
  • In contrast to EC 2.5.1.127, this enzyme does not accept norspermine as a substrate.
 1 A2BIX4
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