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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_3_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 480: Lipoyl synthase 2

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
Lipoyl synthase. [EC: 2.8.1.8]
[Protein]-N(6)-(octanoyl)-L-lysine + an [Fe-S] cluster scaffold protein carrying a [4Fe-4S](2+) cluster + 2 S-adenosyl-L-methionine + 2 oxidized [2Fe-2S] ferredoxin + 6 H(+) = [protein]-N(6)-((R)-dihydrolipoyl)-L- lysine + an [Fe-S] cluster scaffold protein + 2 sulfide + 4 Fe(3+) + 2 L-methionine + 2 5'-deoxyadenosine + 2 reduced [2Fe-2S] ferredoxin.
  • This enzyme catalyzes the final step in the de novo biosynthesis of the lipoyl cofactor, the attachment of two sulfhydryl groups to C(6) and C(8) of a pendant octanoyl chain.
  • It is a member of the 'AdoMet radical' (radical SAM) family, all members of which produce the 5'-deoxyadenosin-5'-yl radical and methionine from AdoMet (S-adenosylmethionine) by the addition of an electron from an iron-sulfur center.
  • The enzyme contains two [4Fe-4S] clusters.
  • The first cluster produces the radicals, which are converted into 5'-deoxyadenosine when they abstract hydrogen atoms from C(6) and C(8), respectively, leaving reactive radicals at these positions that interact with sulfur atoms within the second (auxiliary) cluster.
  • Having donated two sulfur atoms, the auxiliary cluster is degraded during catalysis, but is regenerated immediately by the transfer of a new cluster from iron-sulfur cluster carrier proteins.
  • Lipoylation is essential for the function of several key enzymes involved in oxidative metabolism, as it converts apoprotein into the biologically active holoprotein.
  • Examples of such lipoylated proteins include pyruvate dehydrogenase (E(2) domain), 2-oxoglutarate dehydrogenase (E(2) domain), the branched-chain 2-oxoacid dehydrogenases and the glycine cleavage system (H protein).
  • An alternative lipoylation pathway involves EC 6.3.1.20, which can lipoylate apoproteins using exogenous lipoic acid (or its analogs).
 2 P73572 Q7NFJ9