This is a family of queuine tRNA-ribosyltransferases EC:2.4.2.29, also known as tRNA-guanine transglycosylase and guanine insertion enzyme. Queuine tRNA-ribosyltransferase modifies tRNAs for asparagine, aspartic acid, histidine and tyrosine with que ...
This is a family of queuine tRNA-ribosyltransferases EC:2.4.2.29, also known as tRNA-guanine transglycosylase and guanine insertion enzyme. Queuine tRNA-ribosyltransferase modifies tRNAs for asparagine, aspartic acid, histidine and tyrosine with queuine. It catalyses the exchange of guanine-34 at the wobble position with 7-aminomethyl-7-deazaguanine, and the addition of a cyclopentenediol moiety to 7-aminomethyl-7-deazaguanine-34 tRNA; giving a hypermodified base queuine in the wobble position [1,2]. The aligned region contains a zinc binding motif C-x-C-x2-C-x29-H, and important tRNA and 7-aminomethyl-7deazaguanine binding residues [1].
The PUA domain named after Pseudouridine synthase and Archaeosine transglycosylase, was detected in archaeal and eukaryotic pseudouridine synthases, archaeal archaeosine synthases, a family of predicted ATPases that may be involved in RNA modificatio ...
The PUA domain named after Pseudouridine synthase and Archaeosine transglycosylase, was detected in archaeal and eukaryotic pseudouridine synthases, archaeal archaeosine synthases, a family of predicted ATPases that may be involved in RNA modification, a family of predicted archaeal and bacterial rRNA methylases. Additionally, the PUA domain was detected in a family of eukaryotic proteins that also contain a domain homologous to the translation initiation factor eIF1/SUI1; these proteins may comprise a novel type of translation factors. Unexpectedly, the PUA domain was detected also in bacterial and yeast glutamate kinases; this is compatible with the demonstrated role of these enzymes in the regulation of the expression of other genes [1]. It is predicted that the PUA domain is an RNA binding domain.
Patch-forming domain C2 of tRNA-guanine transglycosylase
Domain C2 of tRNA-guanine transglycosylase is formed by a four-stranded anti-parallel beta-sheet lined with two alpha helices. It has conserved basic residues on the surface of the beta-sheets as does the C-terminal domain PUA, Pfam:PF01472. The cata ...
Domain C2 of tRNA-guanine transglycosylase is formed by a four-stranded anti-parallel beta-sheet lined with two alpha helices. It has conserved basic residues on the surface of the beta-sheets as does the C-terminal domain PUA, Pfam:PF01472. The catalytic domain, TGT has conserved basic residues on the outer surface of the N-terminal three-stranded beta sheet, which closes the barrel, and it is postulated that these basic residues from the three domains form a continuous, positively charged patch to which the tRNA binds [1].
