PROSITE documentation PDOC50890

PUA domain profile

The PUA domain, which has been named after PseudoUridine synthase and Archaeosine-specific transglycosylase, is a small, compact domain that consists of 78-83 amino acid residues. The PUA domain is widely conserved in eukaryotic and archaeal RNA modification enzymes and is found in:

• Archaeal and eukaryotic pseudouridine synthases.
• Archaeosine tRNA-guanine transglycosylases.
• A family of predicted ATPases that may be involved in RNA modification.
• A family of predicted archaeal and bacterial rRNA methylases.
• A conserved family of putative novel eukaryotic translation factors.
• Glutamate 5-kinases (EC 2.7.2.11).

The PUA domain can be found alone or in association with other domains, such as the glutamate kinase domain (see <PDOC00701>), the pseudouridine synthase catalytic domain, the phosphoadenosine phosphosulfate (PAPS) reductase domain, the methylase domain, the TGT domain, or the SUI1 domain (see <PDOC00862 >). The PUA domain is supposed to bind to RNA molecules with complex folded structures [1].

The PUA domain contains highly conserved motifs that center around stretches of hydrophobic residues. The domain also contains two highly conserved positions occupied by small amino acids (primarily glycines) [1]. The resolution of the crystal structure of archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii has shown that the PUA domain consists of two α-helices and six β-strands, and folds into a β-sandwich structure similar to the oligonucleotide-binding (OB)-fold (see <PDB:1IQ8>) [2].

The profile we developed covers the entire PUA domain.