TruB family pseudouridylate synthase (N terminal domain)
Members of this family are involved in modifying bases in RNA molecules. They carry out the conversion of uracil bases to pseudouridine. This family includes TruB, a pseudouridylate synthase that specifically converts uracil 55 to pseudouridine in m ...
Members of this family are involved in modifying bases in RNA molecules. They carry out the conversion of uracil bases to pseudouridine. This family includes TruB, a pseudouridylate synthase that specifically converts uracil 55 to pseudouridine in most tRNAs. This family also includes Cbf5p that modifies rRNA [2].
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.
tRNA-pseudouridine synthase II (TruB) from Thermotoga maritima catalyses the conversion of tRNA uridine to tRNA pseudouridine at position 55 in tRNA. The formation of pseudouridine is shown to be important for the structural integrity of tRNA.
TruB is responsible for the pseudouridine residue present in the T loops of virtually all tRNAs. TruB recognises the preformed 3-D structure of the T loop primarily through shape complementarity. It accesses its substrate uridyl residue by flipping out the nucleotide and disrupts the tertiary structure of tRNA [PMID:11779468].
The catalytic domain consists of two subdomains, each of which has an alpha+beta structure that has some similarity to the ferredoxin-like fold (note: some pseudouridine synthases contain additional domains). The active site is the most conserved structural region of the superfamily and is located between the two homologous domains. There are four distinct families of pseudouridine synthases that share no global sequence similarity, but which do share the same fold of their catalytic domain(s) and uracil-binding site and are descended from a common molecular ancestor. [PMID:10529181]
There is still much debate as to the exact mechanism of this enzyme.
Defined by 4 residues: ASP:A-39TYR:A-67ASP:A-81ARG:A-172
