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CATH Superfamily 3.20.20.105

Queuine tRNA-ribosyltransferase-like

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:

"
Queuine tRNA-ribosyltransferase-like
".

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.

Superfamily EC Annotations

Note: the EC figure is not being displayed for this superfamily as there are more than 100 different EC terms.

There are 3 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
TRNA-guanine(34) transglycosylase. [EC: 2.4.2.29]
(1) Guanine(34) in tRNA + queuine = queuosine(34) in tRNA + guanine. (2) Guanine(34) in tRNA + 7-aminomethyl-7-carbaguanine = 7-aminomethyl-7- carbaguanine(34) in tRNA + guanine.
  • Certain prokaryotic and eukaryotic tRNAs contain the modified base queuine at position 34.
  • In eukaryotes queuine is salvaged from food and incorporated into tRNA directly via a base-exchange reaction, replacing guanine.
  • In eubacteria, which produce queuine de novo, the enzyme catalyzes the exchange of guanine with the queuine precursor preQ(1), which is ultimately modified to queuine.
  • The eubacterial enzyme can also use an earlier intermediate, preQ(0), to replace guanine in unmodified tRNA(Tyr) and tRNA(Asn).
  • This enzyme acts after EC 1.7.1.13 in the queuine-biosynthesis pathway.
 1304 A0A009I0P1 A0A009JHI6 A0A009QDI5 A0A009REY7 A0A009TR35 A0A023PBX1 A0A023YT07 A0A024DCN6 A0A025CA06 A0A026V5D0
(1294 more...)
TRNA-guanine(15) transglycosylase. [EC: 2.4.2.48]
Guanine(15) in tRNA + 7-cyano-7-carbaguanine = 7-cyano-7-carbaguanine(15) in tRNA + guanine.
  • Archaeal tRNAs contain the modified nucleoside archaeosine at position 15.
  • This archaeal enzyme catalyzes the exchange of guanine at position 15 of tRNA with the base preQ(0), which is ultimately modified to form the nucleoside archaeosine (cf. EC 2.6.1.97).
 49 A0A0E3MFS3 A0A0E3PUE8 A0A0E3QR87 A0A0E3R8V9 A0A0E3RSW9 A0A0F8EEE5 A0A1D2WH57 A0A1D2WWY1 A0A328S6V1 A0A495R9X8
(39 more...)
Archaeosine synthase. [EC: 2.6.1.97]
L-glutamine + 7-cyano-7-carbaguanine(15) in tRNA + H(2)O = L-glutamate + archaeine(15) in tRNA.
  • In Euryarchaeota the reaction is catalyzed by ArcS.
  • In Crenarchaeota, which do not have an ArcS homolog, the reaction is catalyzed either by a homolog of EC 6.3.4.20 that includes a glutaminase domain (cf. EC 3.5.1.2), or by a homolog of EC 1.7.1.13.
  • The enzyme from the Euryarchaeon Methanocaldococcus jannaschii can also use arginine and ammonium as amino donors.
 2 D4GTN6 L9VC05