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CATH Superfamily 3.20.20.70

Aldolase class I

The name of this superfamily has been modified since the most recent official CATH+ release (v4_4_0). At the point of the last release, this superfamily was named:

"
Aldolase class I
".

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 509: Biotin synthase

There are 1 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
Biotin synthase. [EC: 2.8.1.6]
Dethiobiotin + sulfur-(sulfur carrier) + 2 S-adenosyl-L-methionine + 2 reduced [2Fe-2S] ferredoxin = biotin + (sulfur carrier) + 2 L-methionine + 2 5'-deoxyadenosine + 2 oxidized [2Fe-2S] ferredoxin.
  • The enzyme binds a [4Fe-4S] and a [2Fe-2S] cluster.
  • In every reaction cycle, the enzyme consumes two molecules of AdoMet, each producing 5'-deoxyadenosine and a putative dethiobiotinyl carbon radical.
  • Reaction with another equivalent of AdoMet results in abstraction of the C6 methylene pro-S hydrogen atom from 9-mercaptodethiobiotin, and the resulting carbon radical is quenched via formation of an intramolecular C-S bond, thus closing the biotin thiophane ring.
  • The sulfur donor is believed to be the [2Fe-2S] cluster, which is sacrificed in the process, so that in vitro the reaction is a single turnover.
  • In vivo, the [2Fe-2S] cluster can be reassembled by the Isc or Suf iron-sulfur cluster assembly systems, to allow further catalysis.
 4 A0A0D5ND48 A0A0D5ND48 Q74CT7 Q74CT7
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